diff --git a/ui/terminal_panel.py b/ui/terminal_panel.py
index e660410..a7bd02c 100644
--- a/ui/terminal_panel.py
+++ b/ui/terminal_panel.py
@@ -583,8 +583,16 @@ class TerminalPanel(QWidget):
         cursor = self.term.textCursor()
         if cursor.atEnd():
             return
-        if cursor.columnNumber() == 0 and not cursor.hasSelection():
+        # 不允许删除当前输入行之前的内容（提示符 root@host:~# 等）
+        if cursor.position() < self._current_line_start:
+            cursor.setPosition(self._current_line_start)
+            self.term.setTextCursor(cursor)
             return
+        # 如果有选区且选区起点在当前输入行之前，不允许
+        if cursor.hasSelection():
+            sel_start = cursor.selectionStart()
+            if sel_start < self._current_line_start:
+                return
         cursor.deleteChar()
 
     def _history_prev(self):