diff --git a/src/sao.less b/src/sao.less
index faa83cc780..7d7c65069f 100644
--- a/src/sao.less
+++ b/src/sao.less
@@ -68,6 +68,7 @@ button {
             overflow: hidden;
             text-overflow: ellipsis;
             min-width: 30px;
+            text-align: center;
         }
         & > tbody > tr > td {
             cursor: pointer;