diff --git a/plugins/sentinel/dashboard.html b/plugins/sentinel/dashboard.html
index 29e4fd5..7ec3d10 100644
--- a/plugins/sentinel/dashboard.html
+++ b/plugins/sentinel/dashboard.html
@@ -322,15 +322,7 @@
           grid.appendChild(card);
           _cardCache[id] = card;
           if (isRow) {
-            // 销毁旧图表实例
-            if (_chartInstances[id]) {
-              ['cpu','mem','net'].forEach(function(k){
-                if (_chartInstances[id][k] && _chartInstances[id][k].canvas) {
-                  var c = _chartInstances[id][k].canvas;
-                  c.getContext('2d').clearRect(0,0,c.width,c.height);
-                }
-              });
-            }
+            if (_chartInstances[id]) { _chartInstances[id] = null; }
             try {
               _chartInstances[id] = { cpu: null, mem: null, net: null };
               if (typeof MiniChart !== 'undefined') {