大神就不用进来看了，分享一个实用的判断写法，自己已经用，GPT帮我写的。

              {if isset($eyou.field.videoyoutube) && !empty($eyou.field.videoyoutube)}
              <div class="layui-colla-item" id="videoSection">
                <h2 class="layui-colla-title product_title_n">Video</h2>
                <div class="layui-colla-content layui-show">
                  <div class="iframe-container">{$eyou.field.videoyoutube}</div>
                </div>
              </div>
              {elseif isset($eyou.field.lanmushiping) && !empty($eyou.field.lanmushiping)}
              <div class="layui-colla-item" id="videoSection">
                <h2 class="layui-colla-title product_title_n">Video</h2>
                <div class="layui-colla-content layui-show">
                  <div class="iframe-container">{$eyou.field.lanmushiping}</div>
                </div>
              </div>
              {else}
              {/if}

解释说明：

栏目视频：