diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3a1a5679d..ebf2dd6a4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,7 +9,8 @@
 - 修复 Clickoutside 报错, #729
 - 修复 DatePicker 选择日期范围时当选中同一天再调整时间会出错
 - 更新 TimePicker 滚动条在 IE10+ 下隐藏
-- 新增 Dropdown 新增 command api #432
+- 新增 Dropdown 的 command api #432
+- 修复 Slider 在 Form 中的显示问题
 
 ### 1.0.0-rc.8
 
diff --git a/packages/theme-default/src/alert.css b/packages/theme-default/src/alert.css
index 6aad469cf..a5ce5b8ef 100644
--- a/packages/theme-default/src/alert.css
+++ b/packages/theme-default/src/alert.css
@@ -60,7 +60,7 @@
 
     & .el-alert__description {
       color: #fff;
-      font-size: var(--alert-description-font-size-font-size);
+      font-size: var(--alert-description-font-size);
       margin: 5px 0 0 0;
     }
 
diff --git a/packages/theme-default/src/common/var.css b/packages/theme-default/src/common/var.css
index 94c544481..c37796b7c 100644
--- a/packages/theme-default/src/common/var.css
+++ b/packages/theme-default/src/common/var.css
@@ -492,7 +492,7 @@
   --slider-stop-background-color: var(--color-grey);
   --slider-disable-color: var(--color-grey);
 
-  --slider-margin: 20px 0;
+  --slider-margin: 16px 0;
   --slider-border-radius: 3px;
   --slider-height: 4px;
   --slider-button-size: 12px;
diff --git a/packages/theme-default/src/message-box.css b/packages/theme-default/src/message-box.css
index a4d91ca99..7b683667d 100644
--- a/packages/theme-default/src/message-box.css
+++ b/packages/theme-default/src/message-box.css
@@ -112,7 +112,7 @@
       }
 
       &.el-icon-circle-cross {
-        color: var(--msgbox-error-color);
+        color: var(--msgbox-danger-color);
       }
     }
   }
diff --git a/packages/theme-default/src/slider.css b/packages/theme-default/src/slider.css
index 68f282194..f8141892c 100644
--- a/packages/theme-default/src/slider.css
+++ b/packages/theme-default/src/slider.css
@@ -81,7 +81,21 @@
       text-align: center;
 
       .el-tooltip {
-        margin-top: 9px;
+        line-height: 1;
+        height: 100%;
+        display: block;
+      }
+
+      .el-tooltip::after {
+        content: '';
+        width: 0;
+        height: 100%;
+        display: inline-block;
+        vertical-align: middle;
+      }
+
+      .el-tooltip__rel {
+        vertical-align: middle;
       }
 
       &:hover,