diff --git a/components/finsh/shell.c b/components/finsh/shell.c
index f28e235b3fed8ffb4c1e5bbc6c9577df817bd9e4..c4708cee111f7e12b7f937762eb92c69a3c63b46 100644
--- a/components/finsh/shell.c
+++ b/components/finsh/shell.c
@@ -122,7 +122,11 @@ void finsh_set_device(const char* device_name)
             rt_device_close(shell->device);
             rt_device_set_rx_indicate(shell->device, RT_NULL);
         }
-
+        
+        /* clear line buffer before switch to new device */
+        memset(shell->line, 0, sizeof(shell->line));
+        shell->line_curpos = shell->line_position = 0;
+    
         shell->device = dev;
         rt_device_set_rx_indicate(dev, finsh_rx_ind);
     }