This paper studied the cause of rainstorm occurred in the Haihe River Basin during 18-20 July, 2016 based on the meteorological data, and made comparison between the “1963.8” and “1996.8” storms. The results show that the rainstorm was caused by superimposing of different weather systems and special terrain. It is closely related to water vapor transmission from the South China Sea and East China. The moving path of the rainstorm was from southwest to northeast along the Taihang Mountains. The main influence weather system was similar to the “1963.8” storm, but different from the “96.8” storm. The moving path was between the “1963.8” and “1996.8” storms.