Low design standards of urban original drainage waterlogging system would increase the frequency of flood disasters. Design storm pattern is an essential basis and prerequisite for formulating the design standards of drainage waterlogging prevention system and has large impact on urban construction and flood management. The same frequency method, SCS method, rainstorm attenuation index method and probability density function (PDF) method have been used to obtain the design storm pattern of Suqian city. Based on the risk joint probability of Copula function, results of the four rain types have been analyzed. Results show that the same frequency method and rainstorm attenuation index method have the similar pattern and risk probability. The rain peak of SCS method is large and the risk probability is small, but the rainfall is less concentrated in the maximum 6h period. Moreover， the PDF method has the similar rain peak with the same frequency method， while the maximum 3h and 6h rainfalls are relatively more concentrative, and the risk probability is the smallest. Results of this research could provide new ideas and references for the development and comparison of rain storm patterns.