form结构

<el-form :model="formData" label-width="80px">
  <el-form-item label="label1">
    <el-input v-model="formData.value1"></el-input>
  </el-form-item>
  <el-form-item>
    <el-button type="primary" @click="onSubmit">提交</el-button>
    <el-button>取消</el-button>
  </el-form-item>
</el-form>

修改el-form-item所有样式

<style lang="less" scoped>
.el-form {
  .el-form-item {
    /deep/ * {
      font-size: 18px;
      color: blue;
    }
  }
}
</style>

只修改label

<style lang="less" scoped>
.el-form {
  .el-form-item {
    /deep/ .el-form-item__label {
      font-size: 18px;
      color: blue;
    }
  }
}
</style>

只修改content

<style lang="less" scoped>
.el-form {
  .el-form-item {
    /deep/ .el-form-item__content {
      * {
        font-size: 18px;
        color: blue;
      }
    }
  }
}
</style>

只修改input

<style lang="less" scoped>
.el-form {
  .el-form-item {
    /deep/ .el-form-item__content {
      input {
        font-size: 18px;
        color: blue;
      }
    }
  }
}
</style>

只修改button

<style lang="less" scoped>
.el-form {
  .el-form-item {
    /deep/ .el-form-item__content {
      button {
        font-size: 18px;
        color: blue;
      }
    }
  }
}
</style>