SOURCE

const DataInputComps = ['Input', 'InputNumber', 'Select', 'DatePicker', 'TimePicker', 'CheckboxGroup', 'RadioGroup', ''];
function searchChildren(children) {
  function search(cc) {
      console.log(1, cc[0].tag)
    for (let i = 0; i < cc.length; i++) {
      const item = cc[i];
      if (DataInputComps.indexOf(item.tag) > -1) {
        return item;
      }
      if (item.children) {
        return search(item.children);
      }
    }
  }
  return search(children);
}

const node = {"id":3,"parentId":2,"ins_id":"","tag":"FormItem",
"data":{"label":"子项label","required":true,"extra":"","$style":{"marginBottom":24,"paddingBottom":8},
"$exports":[{"attrKey":"prop","sortIdx":-1},{"attrKey":"rules","sortIdx":-1},{"attrKey":"labelCol","sortIdx":-1},{"attrKey":"wrapperCol","sortIdx":-1}],"$exportState":true},
"children":[{"id":4,"parentId":3,"tag":"FlexItem","data":{"overflow":"visible","$style":{},"$exports":[],"$exportState":true},"group":true,"ins_id":"","children":[{"id":5,"parentId":4,"ins_id":"c9696c5ef9214e8eaf08dccaf82e3243","tag":"Input","data":{"type":"text","size":"default","placeholder":"请输入文本","maxlength":20,"$style":{},"$exports":[{"attrKey":"value","alias":"","sortIdx":-1},{"attrKey":"disabled","alias":"","sortIdx":-1},{"attrKey":"readonly","alias":"","sortIdx":-1},{"eventKey":"on-change","alias":"change事件","sortIdx":-1},{"eventKey":"on-enter","alias":"enter事件","sortIdx":-1},{"eventKey":"on-click","alias":"click事件","sortIdx":-1},{"eventKey":"on-focus","alias":"focus事件","sortIdx":-1},{"eventKey":"on-blur","alias":"blur事件","sortIdx":-1},{"eventKey":"on-keyup","alias":"keyup事件","sortIdx":-1},{"eventKey":"on-keydown","alias":"keydown事件","sortIdx":-1},{"eventKey":"on-keypress","alias":"keypress事件","sortIdx":-1},{"eventKey":"on-search","alias":"search事件","sortIdx":-1}],"$exportState":true,"$data_sync":{"type":"variable","id":["9c4abf3bb8bf41b5b5446266564de3cf"]}},"$complexInfo":{"id":34,"edit_page_uuid":"e5582ae01cec4a71bb967d1c5cd0b3cb","atom_ins":{"uuid":"99c8a0e3abc441efa127a11db2951175","origin_page_uuid":"sal20000_org_key210421eaeoa86dwc"},"code_tree":{"id":1,"parentId":0,"ins_id":"c9696c5ef9214e8eaf08dccaf82e3243","tag":"Input","data":{"type":"text","size":"default","placeholder":"请输入文本","maxlength":20,"$style":{},"$exports":[{"attrKey":"value","alias":"","sortIdx":-1},{"attrKey":"disabled","alias":"","sortIdx":-1},{"attrKey":"readonly","alias":"","sortIdx":-1},{"eventKey":"on-change","alias":"change事件","sortIdx":-1},{"eventKey":"on-enter","alias":"enter事件","sortIdx":-1},{"eventKey":"on-click","alias":"click事件","sortIdx":-1},{"eventKey":"on-focus","alias":"focus事件","sortIdx":-1},{"eventKey":"on-blur","alias":"blur事件","sortIdx":-1},{"eventKey":"on-keyup","alias":"keyup事件","sortIdx":-1},{"eventKey":"on-keydown","alias":"keydown事件","sortIdx":-1},{"eventKey":"on-keypress","alias":"keypress事件","sortIdx":-1},{"eventKey":"on-search","alias":"search事件","sortIdx":-1}],"$exportState":true,"$data_sync":""},"children":[]}},"children":[]}]}]}
console.log(searchChildren(node.children))