Surface observation dataset of china meteorological administration is used in this paper, by using the definition of scope and intensity of precipitation ,76 processes of heavy precipitation processes in summer of Beijing are screened out. Three evaluation indices including average precipitation of a process, Extreme value of daily precipitation and coverage area are defined to analyze those 76 heavy precipitation process statistically, and then the Beijing summer rainfall process for comprehensive evaluation model is established. First, each index is analyzed by using Johnson normal variation; then, the normal distribution of the inverse function of Johnson variation determines the Corresponding theory value of each single index in in different return period, and the theory values are used as the threshold for the classification; Finally, the variation coefficient method is used to determine the weights of three indicators of the model. By using the model, two heavy precipitation processes of Beijing in July 21, 2012 and July 20, 2016 are evaluated quantitatively，the result shows that those two processes are classified as I Level, the model has certain application value.
Key words: Comprehensive evaluation model; heavy precipitation; Johnson normal variation; return period