diff --git a/peri-tui/src/app/agent_shell_executor.rs b/peri-tui/src/app/agent_shell_executor.rs
index 3424608b..1dd343d8 100644
--- a/peri-tui/src/app/agent_shell_executor.rs
+++ b/peri-tui/src/app/agent_shell_executor.rs
@@ -193,6 +193,7 @@ impl ShellExecutor for AgentShellExecutor {
         // output_rx 全程写磁盘（agent 路径不显示在 UI 输出流，仅写磁盘供详情面板 / 通知读取）。
         // 与 !command 路径不同：那条路径 output_rx 由 App drain 丢弃；本路径交给 DiskOutput。
         peri_agent::task_output::DiskOutput::spawn_writer(output_path.clone(), execution.output_rx);
+        let started_instant = execution.started_instant;
         let process_abort = execution.abort.clone();
 
         // 真正的进程退出信号在 execution.result（peri-tui 的 oneshot）。
@@ -241,7 +242,7 @@ impl ShellExecutor for AgentShellExecutor {
                 Some(background_tx)
             },
             kill: process_abort.clone(),
-            started_instant: std::time::Instant::now(),
+            started_instant,
             direct_background: run_in_background,
         };
         if run_in_background {
diff --git a/peri-tui/src/app/message_pipeline/message_pipeline_test.rs b/peri-tui/src/app/message_pipeline/message_pipeline_test.rs
index d1f2467c..1fa0102a 100644
--- a/peri-tui/src/app/message_pipeline/message_pipeline_test.rs
+++ b/peri-tui/src/app/message_pipeline/message_pipeline_test.rs
@@ -252,6 +252,43 @@ fn test_handle_event_tool_lifecycle() {
     assert!(matches!(actions[0], PipelineAction::None));
 }
 
+#[test]
+fn test_bash_tool_start_uses_spawn_started_at() {
+    let mut pipeline = MessagePipeline::new("/tmp".to_string());
+    let _ = pipeline.handle_event(AgentEvent::ToolStart {
+        tool_call_id: "bash1".into(),
+        name: "Bash".into(),
+        display: "Bash".into(),
+        args: "sleep 10".into(),
+        input: json!({"command": "sleep 10"}),
+        source_agent_id: None,
+    });
+    let tail_vms = pipeline.build_tail_vms();
+    let Some(MessageViewModel::ToolBlock { started_at, .. }) = tail_vms.last() else {
+        panic!("Bash ToolStart 应生成 pending ToolBlock");
+    };
+    assert!(
+        started_at.is_none(),
+        "收到 shell 注册前不应开始 Ctrl+B 计时"
+    );
+
+    let spawned_at = std::time::Instant::now() - std::time::Duration::from_secs(3);
+    assert!(
+        pipeline.set_bash_tool_started_at("sleep 10", spawned_at),
+        "应能按 Bash command 回填真实启动时间"
+    );
+    let tail_vms = pipeline.build_tail_vms();
+    let Some(MessageViewModel::ToolBlock { started_at, .. }) = tail_vms.last() else {
+        panic!("Bash ToolStart 应仍生成 pending ToolBlock");
+    };
+    assert!(
+        started_at
+            .as_ref()
+            .is_some_and(|t| t.elapsed() >= std::time::Duration::from_secs(2)),
+        "Ctrl+B 提示计时应基于真实 spawn 时间"
+    );
+}
+
 /// 测试：handle_event StateSnapshot 更新 completed
 #[test]
 fn test_handle_event_state_snapshot() {
diff --git a/peri-tui/src/app/message_pipeline/mod.rs b/peri-tui/src/app/message_pipeline/mod.rs
index 5f8c0b44..dd39be0b 100644
--- a/peri-tui/src/app/message_pipeline/mod.rs
+++ b/peri-tui/src/app/message_pipeline/mod.rs
@@ -205,6 +205,8 @@ pub(crate) struct PendingTool {
     tool_call_id: String,
     name: String,
     input: serde_json::Value,
+    /// Bash 子进程真实启动时刻；ToolStart 早于 spawn 时保持 None。
+    started_at: Option<Instant>,
 }
 
 /// ToolEnd 后、StateSnapshot 前的工具结果（用于在 reconcile gap 期间显示）
@@ -322,6 +324,23 @@ impl MessagePipeline {
         &self.cwd
     }
 
+    pub(crate) fn set_bash_tool_started_at(&mut self, command: &str, started_at: Instant) -> bool {
+        for pending in self.pending_tools.values_mut() {
+            if pending.name != "Bash" || pending.started_at.is_some() {
+                continue;
+            }
+            let Some(pending_command) = pending.input.get("command").and_then(|v| v.as_str())
+            else {
+                continue;
+            };
+            if pending_command == command {
+                pending.started_at = Some(started_at);
+                return true;
+            }
+        }
+        false
+    }
+
     /// 获取当前流式渲染模式
     pub(crate) fn streaming_mode(&self) -> StreamingMode {
         self.streaming_mode
@@ -438,6 +457,7 @@ impl MessagePipeline {
                             tool_call_id: tool_call_id.to_string(),
                             name: name.to_string(),
                             input,
+                            started_at: None,
                         },
                     );
                 } else {
@@ -692,6 +712,7 @@ impl MessagePipeline {
                 tool_call_id: tool_call_id.to_string(),
                 name: name.to_string(),
                 input,
+                started_at: None,
             },
         );
     }
diff --git a/peri-tui/src/app/message_pipeline/reconcile.rs b/peri-tui/src/app/message_pipeline/reconcile.rs
index f037c426..d0c2af55 100644
--- a/peri-tui/src/app/message_pipeline/reconcile.rs
+++ b/peri-tui/src/app/message_pipeline/reconcile.rs
@@ -220,7 +220,12 @@ impl MessagePipeline {
         for tc in &self.current_ai_tool_calls {
             if let Some(pending) = self.pending_tools.get(&tc.id) {
                 if pending.name != "Agent" {
-                    tail_vms.push(self.build_tool_start_vm(&tc.id, &pending.name, &pending.input));
+                    tail_vms.push(self.build_tool_start_vm(
+                        &tc.id,
+                        &pending.name,
+                        &pending.input,
+                        pending.started_at,
+                    ));
                 }
             }
         }
diff --git a/peri-tui/src/app/message_pipeline/transform.rs b/peri-tui/src/app/message_pipeline/transform.rs
index 10694c1f..fb4e1415 100644
--- a/peri-tui/src/app/message_pipeline/transform.rs
+++ b/peri-tui/src/app/message_pipeline/transform.rs
@@ -126,6 +126,7 @@ impl MessagePipeline {
         tool_call_id: &str,
         name: &str,
         input: &serde_json::Value,
+        started_at: Option<std::time::Instant>,
     ) -> MessageViewModel {
         let display_name = tool_display::format_tool_name(name);
         let args_display = tool_display::format_tool_args(name, input, Some(&self.cwd));
@@ -139,7 +140,7 @@ impl MessagePipeline {
             collapsed: true,
             color: tool_color(name),
             diff_input: None,
-            started_at: Some(std::time::Instant::now()),
+            started_at,
             content_hash: 0,
         };
         vm.recompute_hash();
diff --git a/peri-tui/src/app/shell_command.rs b/peri-tui/src/app/shell_command.rs
index 63b8440c..ac09a556 100644
--- a/peri-tui/src/app/shell_command.rs
+++ b/peri-tui/src/app/shell_command.rs
@@ -72,6 +72,50 @@ impl ShellCommandPool {
     }
 }
 
+fn set_pending_bash_tool_started_at_in_view(
+    view_messages: &mut [MessageViewModel],
+    command: &str,
+    started_at: std::time::Instant,
+) -> bool {
+    for vm in view_messages.iter_mut().rev() {
+        let matched = match vm {
+            MessageViewModel::ToolBlock {
+                tool_name,
+                args_display,
+                content,
+                is_error,
+                started_at: vm_started_at,
+                ..
+            } => {
+                tool_name == "Bash"
+                    && content.is_empty()
+                    && !*is_error
+                    && vm_started_at.is_none()
+                    && args_display
+                        .as_deref()
+                        .is_some_and(|args| bash_args_display_matches_command(args, command))
+            }
+            _ => false,
+        };
+        if matched {
+            if let MessageViewModel::ToolBlock {
+                started_at: vm_started_at,
+                ..
+            } = vm
+            {
+                *vm_started_at = Some(started_at);
+            }
+            vm.recompute_hash();
+            return true;
+        }
+    }
+    false
+}
+
+fn bash_args_display_matches_command(args_display: &str, command: &str) -> bool {
+    args_display == command || args_display == super::tool_display::truncate(command, 400)
+}
+
 impl App {
     pub(crate) fn running_background_shell_task_count(&self) -> usize {
         let session = self.session_mgr.current();
@@ -161,7 +205,7 @@ impl App {
             },
             output_rx: Some(execution.output_rx),
             result_rx: Some(execution.result),
-            started_instant: std::time::Instant::now(),
+            started_instant: execution.started_instant,
         };
     }
 
@@ -493,6 +537,9 @@ impl App {
     pub fn register_agent_shell(&mut self, reg: super::AgentShellRegistration) {
         let direct_background = reg.direct_background;
         let mut slot = super::AgentShellSlot::from_registration(reg);
+        if !direct_background {
+            self.set_agent_bash_tool_started_at(&slot.command, slot.started_instant);
+        }
         // 直接后台命令启动 stall watchdog（检测卡在等待输入）
         if direct_background {
             let watchdog = super::background_shell::spawn_stall_watchdog(
@@ -507,6 +554,24 @@ impl App {
         self.render_rebuild();
     }
 
+    fn set_agent_bash_tool_started_at(
+        &mut self,
+        command: &str,
+        started_at: std::time::Instant,
+    ) -> bool {
+        let session = self.session_mgr.current_mut();
+        let pipeline_changed = session
+            .messages
+            .pipeline
+            .set_bash_tool_started_at(command, started_at);
+        let view_changed = set_pending_bash_tool_started_at_in_view(
+            &mut session.messages.view_messages,
+            command,
+            started_at,
+        );
+        pipeline_changed || view_changed
+    }
+
     /// 把当前会话中所有前台 agent shell 后台化（Ctrl+B 触发）。
     ///
     /// 与 [`Self::background_foreground`]（!command 路径）协同：Ctrl+B 时先尝试
@@ -672,7 +737,7 @@ impl App {
             output_path,
             execution.result,
             execution.abort,
-            std::time::Instant::now(),
+            execution.started_instant,
         );
         bg.stall_watchdog = Some(watchdog);
         self.session_mgr.current_mut().background_shells.push(bg);
diff --git a/peri-tui/src/app/shell_command_test.rs b/peri-tui/src/app/shell_command_test.rs
index 031d8216..fe33a020 100644
--- a/peri-tui/src/app/shell_command_test.rs
+++ b/peri-tui/src/app/shell_command_test.rs
@@ -48,6 +48,33 @@ fn make_agent_shell_slot(
     (AgentShellSlot::from_registration(reg), exit_signal)
 }
 
+#[test]
+fn test_set_pending_bash_tool_started_at_in_view() {
+    let command = "echo hello";
+    let mut view_messages = vec![MessageViewModel::tool_block(
+        "Bash".to_string(),
+        "Bash".to_string(),
+        Some(command.to_string()),
+        false,
+    )];
+    let spawned_at = std::time::Instant::now() - std::time::Duration::from_secs(3);
+
+    assert!(
+        set_pending_bash_tool_started_at_in_view(&mut view_messages, command, spawned_at),
+        "应能回填当前 view 中的 pending Bash ToolBlock"
+    );
+
+    let MessageViewModel::ToolBlock { started_at, .. } = &view_messages[0] else {
+        panic!("测试数据应为 ToolBlock");
+    };
+    assert!(
+        started_at
+            .as_ref()
+            .is_some_and(|t| t.elapsed() >= std::time::Duration::from_secs(2)),
+        "回填后 Ctrl+B 提示应按真实 spawn 时间计时"
+    );
+}
+
 #[tokio::test]
 async fn test_merge_shell_records_inserts_after_anchor_without_origin_messages() {
     let (app, _handle) = App::new_headless(80, 24).await;
diff --git a/peri-tui/src/shell_exec.rs b/peri-tui/src/shell_exec.rs
index 6007e3a6..9fd27731 100644
--- a/peri-tui/src/shell_exec.rs
+++ b/peri-tui/src/shell_exec.rs
@@ -1,4 +1,4 @@
-use std::process::Stdio;
+use std::{process::Stdio, time::Instant};
 
 use anyhow::{Context, Result};
 use peri_agent::encoding::decode_output_bytes;
@@ -108,6 +108,8 @@ pub struct ShellExecution {
     pub abort: ShellAbortHandle,
     /// 流式输出 channel（stdout + stderr 合并推送）
     pub output_rx: mpsc::Receiver<Vec<u8>>,
+    /// 子进程成功 spawn 后的真实启动时刻。
+    pub started_instant: Instant,
 }
 
 /// 流式执行 shell 命令：stdout/stderr 通过 `output_rx` 流式推送，进程退出时
@@ -126,38 +128,48 @@ pub fn execute_shell_command_streaming(
     let (output_tx, output_rx) = mpsc::channel::<Vec<u8>>(256);
     let (result_tx, result_rx) = oneshot::channel::<Result<CommandOutput>>();
 
-    let cmd_str = command.to_string();
-    let cwd_str = cwd.to_string();
-    let handle = tokio::spawn(async move {
-        let result = run_streaming(&cmd_str, &cwd_str, stdin_rx, output_tx).await;
-        // task 被 abort 时 result_tx drop，result_rx 收到 Canceled，调用方需处理
-        let _ = result_tx.send(result);
-    });
-    let abort = ShellAbortHandle::from_tokio_abort(handle.abort_handle());
-    drop(handle);
+    match spawn_streaming_child(command, cwd, stdin_rx.is_some()) {
+        Ok((child, started_instant)) => {
+            let handle = tokio::spawn(async move {
+                let result = run_streaming_child(child, stdin_rx, output_tx).await;
+                // task 被 abort 时 result_tx drop，result_rx 收到 Canceled，调用方需处理
+                let _ = result_tx.send(result);
+            });
+            let abort = ShellAbortHandle::from_tokio_abort(handle.abort_handle());
+            drop(handle);
 
-    ShellExecution {
-        result: result_rx,
-        abort,
-        output_rx,
+            ShellExecution {
+                result: result_rx,
+                abort,
+                output_rx,
+                started_instant,
+            }
+        }
+        Err(error) => {
+            drop(output_tx);
+            let _ = result_tx.send(Err(error));
+            ShellExecution {
+                result: result_rx,
+                abort: ShellAbortHandle::noop(),
+                output_rx,
+                started_instant: Instant::now(),
+            }
+        }
     }
 }
 
-/// 流式执行的实际逻辑：spawn 子进程，stdout/stderr 流式读取推送 + 累积，
-/// 进程退出后返回累积的 CommandOutput。
-async fn run_streaming(
+fn spawn_streaming_child(
     command: &str,
     cwd: &str,
-    mut stdin_rx: Option<mpsc::Receiver<String>>,
-    output_tx: mpsc::Sender<Vec<u8>>,
-) -> Result<CommandOutput> {
+    has_stdin: bool,
+) -> Result<(tokio::process::Child, Instant)> {
     let command = streaming_command_with_unbuffered_interpreters(command);
     let mut cmd = peri_middlewares::process::shell_command(&command, &[]);
     apply_streaming_unbuffered_env(&mut cmd);
     if !cwd.trim().is_empty() {
         cmd.current_dir(cwd);
     }
-    if stdin_rx.is_some() {
+    if has_stdin {
         cmd.stdin(Stdio::piped());
     } else {
         cmd.stdin(Stdio::null());
@@ -166,10 +178,21 @@ async fn run_streaming(
         .stderr(Stdio::piped())
         .kill_on_drop(true);
 
-    let mut child = cmd
+    let child = cmd
         .spawn()
         .with_context(|| format!("Failed to spawn shell command: {}", command))?;
+    let started_instant = Instant::now();
+
+    Ok((child, started_instant))
+}
 
+/// 流式执行的实际逻辑：stdout/stderr 流式读取推送 + 累积，
+/// 进程退出后返回累积的 CommandOutput。
+async fn run_streaming_child(
+    mut child: tokio::process::Child,
+    mut stdin_rx: Option<mpsc::Receiver<String>>,
+    output_tx: mpsc::Sender<Vec<u8>>,
+) -> Result<CommandOutput> {
     // stdin 写入 task（与 execute_shell_command_with_stdin 一致）
     if let Some(mut rx) = stdin_rx.take() {
         if let Some(mut stdin) = child.stdin.take() {
diff --git a/peri-tui/src/ui/message_view/mod.rs b/peri-tui/src/ui/message_view/mod.rs
index edebb6e6..fd1b5756 100644
--- a/peri-tui/src/ui/message_view/mod.rs
+++ b/peri-tui/src/ui/message_view/mod.rs
@@ -105,7 +105,7 @@ pub enum MessageViewModel {
         color: Color,
         /// 内嵌 diff 视图输入（Write/Edit 工具执行成功后填充，由 render_thread 按当前 width 渲染）
         diff_input: Option<peri_widgets::DiffInput>,
-        /// pending 时的启动时间（用于渲染 "Ctrl+B to run in background" 2 秒提示）
+        /// pending Bash 子进程真实启动时间；None 表示尚未收到 shell 注册。
         started_at: Option<std::time::Instant>,
         /// 预计算的语义 hash（构造/变更时更新，rebuild 直接读取避免重算）
         content_hash: u64,
@@ -207,6 +207,7 @@ impl PartialEq for MessageViewModel {
                     content: a_content,
                     is_error: a_err,
                     diff_input: a_diff,
+                    started_at: a_started,
                     ..
                 },
                 MessageViewModel::ToolBlock {
@@ -216,6 +217,7 @@ impl PartialEq for MessageViewModel {
                     content: b_content,
                     is_error: b_err,
                     diff_input: b_diff,
+                    started_at: b_started,
                     ..
                 },
             ) => {
@@ -225,6 +227,7 @@ impl PartialEq for MessageViewModel {
                     && a_content == b_content
                     && a_err == b_err
                     && a_diff == b_diff
+                    && a_started.is_some() == b_started.is_some()
             }
             (
                 MessageViewModel::ShellCommand {
@@ -357,6 +360,7 @@ impl Hash for MessageViewModel {
                 is_error,
                 collapsed,
                 diff_input,
+                started_at,
                 ..
             } => {
                 2u8.hash(state);
@@ -368,6 +372,7 @@ impl Hash for MessageViewModel {
                 is_error.hash(state);
                 collapsed.hash(state);
                 diff_input.hash(state);
+                started_at.is_some().hash(state);
             }
             MessageViewModel::ShellCommand {
                 id,
@@ -928,7 +933,7 @@ impl MessageViewModel {
             collapsed: true,
             color,
             diff_input: None,
-            started_at: Some(std::time::Instant::now()),
+            started_at: None,
             content_hash: 0,
         };
         vm.recompute_hash();