Abstract: Based on the hour and minute precipitation data of ground observation in Sichuan Province,nine kinds of merged precipitation products developed by the National Meteorological Information Center were compared and assessed in the first regional rainstorm process in 2019 in Sichuan by using several assessment indicators. The results show that four kinds of 24h merged precipitation products (CMPAS_24h_RT05,CMPAS_24h_NRT05,CMPAS_24h_RT01, CMPAS_24h_NRT01),four kinds of 1h merged precipitation products (CMPAS_RT05,CMPAS_NRT05,CMPAS_RT01,CMPAS_NRT01) and one kind of 10min merged precipitation products (CMPAS_10MIN05) can better reflect the spatiotemporal change trend of heavy rainfall area,but the maximum values are underestimated compared with the actual precipitation. In general,the quality of merged precipitation products is high,which has a good monitoring ability for heavy precipitation,the cumulative precipitation is equivalent to the actual precipitation,the correlation coefficient between 1h merged precipitation products and the actual precipitation is more than 0.924,the sunny and rainy accuracy rate is more than 94.4%,and the correlation coefficient between 10min merged precipitation products and the actual precipitation is 0.85,the TS score of both products decrease with the increase of precipitation magnitude. In contrast,the 1km products are better than 5km products,the near real-time products are better than real-time products,1h products are better than 10min products. The total 1h precipitation of merged products and 24h merged precipitation products are the same,the precipitation of 10min and 1h is not the same,but the difference between them is not big.