Based on multi-source observation data and data fusion and assimilation technology, National Meteorological Information Center has developed and released real-time analysis products that has passed the industry admittance review. In order to ensure the objectivity and authenticity of the evaluation results of the real-time analysis products, the representativeness of the data source—ground station data participating in the inspection and evaluation of the products was studied. 10 precipitation impact indicators such as longitude and latitude, slope, slope direction and data availability of ground meteorological stations from May to August 2020 were selected. On the basis of indicator screening, the weight of each impact indicator to form a comprehensive impact indicator of each station was determined by using correlation analysis, principal component analysis, and grading inspection of the comprehensive impact indicator were conducted. The results show that five of the 10 impact indicators are retained after screening, and their weights from large to small are data availability, equipment stability, slope variability, surface roughness and altitude. The comprehensive impact value of stations in Sichuan Basin is mostly above 0.9, and the stations with low comprehensive impact values are mainly distributed in Ganzi, Aba and Liangshan prefectures of Sichuan Province, which is closely related to the complex terrain and poor representativeness of station in these areas. Through the grading evaluation of the comprehensive impact index, it is reasonable to take the data of stations with the comprehensive impact index value above 0.8 as the "true value" data source for the evaluation of precipitation real-time analysis products.