本文介绍了一台曲轴箱回流扫气的二冲程天然气发动机换气过程的试验研究。文中着重介绍了水模拟动态扫气试验的原理、设备、方法和结果。并对测取扫气图试验方法和水模拟动态扫气试验方法进行了比较。最后介绍了此种测试方法在实际样机改进中应用时的效果。 This paper presents an experimental study on the scavenging process of a two-stroke natural gas engine with a crankcase recirculation scavenger. The paper mainly introduces the principle, equipment, method and result of dynamic simulation of water scavenging. The comparison between the method of scavenging test and the method of dynamic scavenging test of water simulation were carried out. Finally, the effect of this kind of test method applied in the actual prototype improvement is introduced.