Based on the daily precipitation data of 5 meteorological stations in Suzhou from 1981 to 2015, this paper analyzed the frequency of occurrence of rainstorm in Suzhou by Morlet wavelet analysis method, extracted the oscillation period of time series to investigate the change characteristics in different periods. Time series trend analysis and abrupt change test of rainstorm days and rainstorm amount in Suzhou in recent 35 years were conducted by the Mann-Kendall (M-K) nonparametric test. The results show that the rainstorm in the south is more frequent than that in the north of Suzhou from 1981 to 2015, and occurs mainly from June to August. Although the rainstorm days and rainstorm amount fluctuated obviously every year in recent 35 years in Suzhou, it showed a rising trend on the whole. The rainstorm frequency of Suzhou has a complex nesting structure on the multiple time scales, including 5 to 12 years and 3 to 7 years of short-term cycle variation, about 5 years oscillation cycle generated after 1998, and about 27 years of medium-term shock cycle. Suzhou rainstorm has remarkable abrupt changes in 2002, approaching to the upper horizontal borderline of 95% by 2008, but decreasing slowly after 2008.