1、配置字典项

2、html代码：修改下拉选项框

    <div class="col-xs-6">
		<div class="form-group">
			<label class="control-label col-sm-4" title="">
				<span class="required">*</span> ${text('单位')}：<i class="fa icon-question hide"></i></label>
			<div class="col-sm-8">
				<#form:select path="dw" dictType="lz_office"  onchange="categoryChg()"  blankOption="true" class="form-control required" />
			</div>
		</div>
	</div>
	<div class="col-xs-6">
		<div class="form-group">
			<label class="control-label col-sm-4" title="">
				<span class="required">*</span> ${text('部门')}：<i class="fa icon-question hide"></i></label>
			<div class="col-sm-8">
				<#form:select path="bm" dictType="lz_office" blankOption="true" class="form-control required" />
			</div>
		</div>
	</div>

3、js代码

<script>
var purchaseTypeJson;
$(function () {
	$.ajax({
		type:"POST",
		url:"${ctx}/sys/dictData/treeData?dictType=lz_office",
		dataType:"json",
		success: function(json){
			purchaseTypeJson = json;
			var category = $('#dw option:selected').val();
			var categorySelect = $("#dw")[0];
			categorySelect.options.length=1;

			var type = $('#bm option:selected').val();
			var typeSelect = $("#bm")[0];
			typeSelect.options.length=1;
			//往父级下拉框中追加父级字典
			for (var i of json) {
				if (i.pId == "0") {
					var option = new Option(i.name, i.value, false, i.value == category);
					categorySelect.options.add(option);
				}
			}
			//进行循环判断并追加数据到二级下拉框中
			var pid = "";
			for (var i of purchaseTypeJson) {
				if (i.pId == "0" && i.value == category) {
					pid = i.id;
					continue;
				}
			}
			for (var i of json) {
				if (i.pId == pid) {
					var option = new Option(i.name, i.value, false, i.value == type);
					typeSelect.options.add(option);
				}
			}
		}
	});
});

function categoryChg() {

	var category = $('#dw option:selected').val(); //父级下拉框选中的值
	var pid ="";

	var typeSelect = $("#bm")[0];  //清空原来下拉框的值
	typeSelect.options.length = 1;

	//进行循环判断并追加数据到二级下拉框中
	for (var i of purchaseTypeJson) {
		if (i.pId == "0" && i.value == category) {
			pid = i.id;
			continue;
		}
	}
	for (var i of purchaseTypeJson) {
		console.info("jjj:" + i.value.substr(0, 3));
		console.info("iii:" + category);
		console.info("pidpid:" + pid);
		if (i.pId == pid) {
			typeSelect.options.add(new Option(i.name, i.value));  //往下拉框中追加值
		}
	}
}
</script>

4、页面效果