diff --git a/src/platforms/h5/view/bridge/subscribe/index.js b/src/platforms/h5/view/bridge/subscribe/index.js
index 900d2f2c5bfceb8f83928558f346664c1030e800..7c51cc5ec33295dedb8400c0550e4f0ca505f847 100644
--- a/src/platforms/h5/view/bridge/subscribe/index.js
+++ b/src/platforms/h5/view/bridge/subscribe/index.js
@@ -23,10 +23,11 @@ const passiveOptions = supportsPassive ? {
 
 function updateCssVar (vm) {
   if (uni.canIUse('css.var')) {
+    const uniConfigTabbarHeight = parseFloat(__uniConfig.tabBar.height)
     const pageVm = vm.$parent.$parent
     const navigationBarType = pageVm.navigationBar.type
     const windowTopValue = navigationBarType === 'default' || navigationBarType === 'float' ? NAVBAR_HEIGHT : 0
-    const windowBottomValue = getApp().$children[0].showTabBar ? TABBAR_HEIGHT : 0
+    const windowBottomValue = getApp().$children[0].showTabBar ? isNaN(uniConfigTabbarHeight) ? TABBAR_HEIGHT : uniConfigTabbarHeight : 0
     const envMethod = uni.canIUse('css.env') ? 'env' : (uni.canIUse('css.constant') ? 'constant' : '')
     const windowTop = windowTopValue && envMethod ? `calc(${windowTopValue}px + ${envMethod}(safe-area-inset-top))`
       : `${windowTopValue}px`
@@ -87,4 +88,4 @@ export default function initSubscribe (subscribe) {
       })
     }
   })
-}
+}