SOURCE

<div class="wrap">
  <div class="box">
  </div>
  <div class="box">
    <div class="content">
      <span class="label">【NO.1】</span>
      <span class="title">植保所5号小麦地土壤水分过低，需要及时浇水植保所5号小麦地土壤水分过低，需要及时浇水</span>
    </div>
    <div class="content">
      <span class="label">【NO.1】</span>
      <span class="title">植保所5号小麦地土壤水分过低，需要及时浇水植保所5号小麦地土壤水分过低，需要及时浇水</span>
    </div>
  </div>
</div>

.wrap {
  display: flex;
}
.box {
  display: flex;
  flex: 1;
  flex-direction: column;
  flex-shrink: 0;
  border: 1px solid red;
  width: 0;
}
.title {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}