diff --git a/cmdb-ui/src/modules/cmdb/api/dcim.js b/cmdb-ui/src/modules/cmdb/api/dcim.js
index 41c609f..bc7b80e 100644
--- a/cmdb-ui/src/modules/cmdb/api/dcim.js
+++ b/cmdb-ui/src/modules/cmdb/api/dcim.js
@@ -84,3 +84,10 @@ export function getDCIMHistoryOperate(params) {
     params
   })
 }
+
+export function calcUnitFreeCount() {
+  return axios({
+    url: `/v0.1/dcim/rack/calc_u_free_count`,
+    method: 'POST'
+  })
+}
diff --git a/cmdb-ui/src/modules/cmdb/lang/en.js b/cmdb-ui/src/modules/cmdb/lang/en.js
index a268134..2da1cba 100644
--- a/cmdb-ui/src/modules/cmdb/lang/en.js
+++ b/cmdb-ui/src/modules/cmdb/lang/en.js
@@ -894,7 +894,11 @@ if __name__ == "__main__":
         deviceName: 'Device Name',
         removeDevice: 'Remove Device',
         moveDevice: 'Move Device',
-        rackDetail: 'Rack Detail'
+        rackDetail: 'Rack Detail',
+        calcUnitFreeCount: 'Calculate Rack Free Unit Count',
+        calcUnitFreeCountTip: 'Calculating in the background, refresh the page later to see the result',
+        calcUnitFreeCountTip1: 'Calculate Trigger Success, refresh the page later to see the result',
+        calcUnitFreeCountTip2: `Confirm that you want to calculate the number of free Units for all rack?`
     }
 }
 export default cmdb_en
diff --git a/cmdb-ui/src/modules/cmdb/lang/zh.js b/cmdb-ui/src/modules/cmdb/lang/zh.js
index c188140..1e98ce3 100644
--- a/cmdb-ui/src/modules/cmdb/lang/zh.js
+++ b/cmdb-ui/src/modules/cmdb/lang/zh.js
@@ -893,7 +893,11 @@ if __name__ == "__main__":
         deviceName: '设备名',
         removeDevice: '删除设备',
         moveDevice: '移动设备',
-        rackDetail: '机柜详情'
+        rackDetail: '机柜详情',
+        calcUnitFreeCount: '计算机柜空闲U数',
+        calcUnitFreeCountTip: '后台计算中，稍后刷新页面查看结果',
+        calcUnitFreeCountTip1: '计算触发成功，稍后刷新页面查看结果',
+        calcUnitFreeCountTip2: '确认要计算所有机柜的空闲U数？'
     }
 }
 export default cmdb_zh
diff --git a/cmdb-ui/src/modules/cmdb/views/dcim/components/dcimTree.vue b/cmdb-ui/src/modules/cmdb/views/dcim/components/dcimTree.vue
index d85d50b..7af0af0 100644
--- a/cmdb-ui/src/modules/cmdb/views/dcim/components/dcimTree.vue
+++ b/cmdb-ui/src/modules/cmdb/views/dcim/components/dcimTree.vue
@@ -21,11 +21,24 @@
             <a>
               <a-icon
                 type="plus-circle"
-                class="dcim-tree-header-add-icon"
+                class="dcim-tree-header-menu-icon"
               />
               {{ $t(addActionTitle[type]) }}
             </a>
           </a-menu-item>
+
+          <a-menu-item
+            class="dcim-tree-header-calc"
+            @click="calcUnitFreeCount"
+          >
+            <a>
+              <ops-icon
+                type="veops-refresh"
+                class="dcim-tree-header-menu-icon"
+              />
+              {{ $t('cmdb.dcim.calcUnitFreeCount') }}
+            </a>
+          </a-menu-item>
         </a-menu>
       </a-dropdown>
     </div>
@@ -121,7 +134,7 @@
 <script>
 import _ from 'lodash'
 import { DCIM_TYPE, DCIM_TYPE_NAME_MAP } from '../constants.js'
-import { deleteDCIM } from '@/modules/cmdb/api/dcim.js'
+import { deleteDCIM, calcUnitFreeCount } from '@/modules/cmdb/api/dcim.js'
 import CIDetailDrawer from '@/modules/cmdb/views/ci/modules/ciDetailDrawer.vue'
 
 export default {
@@ -153,7 +166,9 @@ export default {
       ],
 
       viewDetailCITypeId: 0,
-      viewDetailAttrObj: {}
+      viewDetailAttrObj: {},
+
+      calculatedFreeUnitCount: false,
     }
   },
   computed: {
@@ -259,6 +274,23 @@ export default {
           this.$refs.CIdetailRef.create(node._id)
         })
       })
+    },
+
+    calcUnitFreeCount() {
+      if (this.calculatedFreeUnitCount) {
+        this.$message.info(this.$t('cmdb.dcim.calcUnitFreeCountTip'))
+      } else {
+        this.$confirm({
+          title: this.$t('tip'),
+          content: this.$t('cmdb.dcim.calcUnitFreeCountTip2'),
+          onOk: () => {
+            calcUnitFreeCount().then(() => {
+              this.calculatedFreeUnitCount = true
+              this.$message.success(this.$t('cmdb.dcim.calcUnitFreeCountTip1'))
+            })
+          }
+        })
+      }
     }
   }
 }
@@ -281,7 +313,11 @@ export default {
       padding: 0px;
     }
 
-    &-add-icon {
+    &-calc {
+      border-top: dashed 1px #e8e8e8;
+    }
+
+    &-menu-icon {
       margin-right: 6px;
     }
   }