uni-forms 有个属性 :labelWidth="数字" 就ok了
<u-form :model="form" ref="uForm">
<u-form-item label="姓名" :labelWidth='140'>
<u-input v-model="name" />
</u-form-item>
<u-form-item label="联系电话" :labelWidth='140'>
<u-input v-model="name" />
</u-form-item>
<u-form-item label="上次登陆" :labelWidth='140'>
<u-input v-model="name" />
</u-form-item>
</u-form>