vue Cannot read property 'company_name' of

Question

<el-input class="pull-left" v-model="params.company_name"></el-input>我定义的data () {      return {        params: {          company_name: '',          site_name: '',          domain: '',          adress: '',          registered_assets: '',          legal: '',          type: 1,          reason: ''        }      }    },运行出现错误   Cannot read property 'company_name' of undefined  怎么解决？？