diff --git a/src/base/combination/combo.js b/src/base/combination/combo.js
index c9bbfc773..2e9b1b9d9 100644
--- a/src/base/combination/combo.js
+++ b/src/base/combination/combo.js
@@ -345,7 +345,8 @@
                     if (width > 500) {
                         maxW = 500;
                     } else if(width > maxW) {
-                        maxW = width;
+                        // 防止小数导致差那么一点
+                        maxW = width + 1;
                     }
                 }