The extreme characteristics of the "21.7" rainstorm in Henan Province from July 19 to 21, 2021, including the impact range, duration, rainfall intensity, and cumulative precipitation, were analyzed using national precipitation data. Based on ERA5 reanalysis data and the generalized Omega equation, key physical factors affecting vertical movement were studied, and the differences from the "75.8" rainstorm were discussed. The results show that about 10% of the stations in Henan Province accumulated precipitation exceeding 500mm during the "21.7" rainstorm, with an average precipitation of 92.8mm on the 20th July 2021, ranking first since 1961. On that day, the hourly precipitation at 16:00-17:00 in Zhengzhou (201.9mm) broke the extreme hourly record in Chinese Mainland. Both the "21.7" and "75.8" rainstorm were accompanied by the transport of water vapor from typhoon flows. The water vapor of the "21.7" rainstorm mainly came from the vapor transport of the southeastern jet stream between Typhoon "Fireworks" and the sub-high, while the "75.8" rainstorm had two water vapor channels: the southwest airflow from the Indian Ocean and the southeast airflow from the Western Pacific. In both rainstorms, the total Q-vector divergence anomalies of the generalized Omega equation corresponded to areas of strong vertical movement. The vertical velocity intensity and total Q-vector divergence intensity of the "21.7" rainstorm was slightly weaker than that of the "75.8" rainstorm. The vertical motion of the "21.7" rainstorm was mainly causd by the combination of low-level dynamics and thermal forcing. For the "75.8" rainstorm, vertical motion was primarily caused by the middle-low level thermal forcing and low-level dynamic forcing. The different distribution of vertical motion in the spatial may be one of the reasons why Zhengzhou area is more prone to the occurrence of short-duration intense precipitation with low centroids and high efficiency.