您好,我这里测试试试可以出来的,您访问下这个服务看看
var provider = new Cesium.WebMapServiceImageryProvider({ url : 'https://basemap.nationalmap.gov/arcgis/services/USGSHydroCached/MapServer/WMSServer', layers : '0', proxy: new Cesium.DefaultProxy('/proxy/') }); viewer.imageryLayers.addImageryProvider(provider);