以云南临沧铀矿为例，介绍了确定覆盖材料降氡效果的野外方法——覆盖试验，包括试验原理、试验场地尺寸确定、试验方法、降氡效果预测、覆盖材料选择及覆盖厚度的确定 Taking Lincang uranium in Yunnan Province as an example, the field methods for determining the radon lowering effect of covering materials, such as the test principle, the size of the test site, the test method, the prediction of the radon lowering effect, the selection of the covering material and the thickness of the covering material, are introduced