Based on the daily rainfall data and flood data during the flood season(from April to October)from 1956 to 2015 in Yining City, by using three methods of linear tend estimation, M-K abrupt change analysis and R/S analysis, the characteristics of heavy rainfall change in recent 60 years and its impact on flood were analyzed. Results showed that the interannual variation of heavy rainfall showed an increasing trend and played a leading role in total rainfall. The proportion of total precipitation increased year by year. June and July were the concentrated months of heavy rainfall and flood, and the annual increase of heavy rainfall is stronger than that of other months. The frequency of floods increased significantly after 1986, with a frequency of about 9 times every 10 years. The frequency of flood occurrence was highly correlated with heavy rainfall. When the precipitation was greater than 15mm, it was easy to cause floods, and the probability was greater than 1/4. The heavy rainfall sequence had a good Hearst phenomenon, and would continue to maintain an increasing trend in the future.