成功el-menu设置菜单高度

主菜单页面
<el-menu
        :default-active="activeMenu"
        :collapse="isCollapse"
        :background-color="variables.menuBg"
        :text-color="variables.menuText"
        :unique-opened="true"
        :active-text-color="variables.menuActiveText"
        :collapse-transition="false"
        mode="vertical"
        style="color:green;"
      >
        <sidebar-item
          v-for="route in routesToShow"
          :key="route.path"
          :item="route"
          :base-path="route.path"
        />
      </el-menu>
<style scoped>
 
.el-menu-item,>>> .el-submenu__title {
  height: 46px;
  line-height: 46px;
  color: red;
}
</style>
加上上面这个样式
子菜单页面
<template>
  <div v-if="!item.hidden">
    <template
      v-if="hasOneShowingChild(item.children,item) && (!onlyOneChild.children||onlyOneChild.noShowingChildren)&&!item.alwaysShow"
    >
      <app-link v-if="onlyOneChild.meta" :to="resolvePath(onlyOneChild.path)">
        <el-menu-item
          :index="resolvePath(onlyOneChild.path)"
          :class="{'submenu-title-noDropdown':!isNest}"
          style="height:46px;line-height:46px;"//这里设置菜单高度
        >
          <item
            :icon="onlyOneChild.meta.icon||(item.meta&&item.meta.icon)"
            :title="onlyOneChild.meta.title"
          />
        </el-menu-item>
      </app-link>
    </template>

    <el-submenu v-else ref="subMenu" :index="resolvePath(item.path)" popper-append-to-body >
      <template slot="title">
        <item v-if="item.meta" :icon="item.meta && item.meta.icon" :title="item.meta.title" />
      </template>
      <sidebar-item
        v-for="child in item.children"
        :key="child.path"
        :is-nest="true"
        :item="child"
        :base-path="resolvePath(child.path)"
        class="nest-menu"
      />
    </el-submenu>
  </div>
</template>