在NGUI中播放Spine动画时出现层级交替闪烁的问题，可能是由于Unity的批处理器在优化绘制调用时错误地重新分组了多个骨架的附件多边形。为了防止这种排序错误，可以参考spine-unity运行时文档。此外，确保在Spine动画的设置中正确配置了渲染顺序和层级。

@zzy569151598 Spinebot's link was a bit too general. See this section here.
At the SkeletonAnimation component enable Advanced - Fix Draw Order to see if this prevents the issue, as it prevents the URP batcher from combining things too aggressively.

If it does not help, adding a SortingGroup at the SkeletonAnimation GameObject is another option, might even be preferrable over the above solution with Fix Draw Order.