Abstract: Based on the linear trend regression analysis method, the trend analysis of the measured flow data of Shashi station in the Changjiang main stream from 1991 to 2017 was carried out. The results show that: 1. From 1991 to 2017, the daily minimum flow in flood season of Shashi hydrological station showed an upward trend, while the daily average flow and the daily maximum flow showed a downward trend; 2.After the operation of the Three Gorges Project in 2003, the daily average flow of Shashi hydrological station during the flood season decreased by 2046 m3/s, or 10.77%, compared with that before the operation.