Based on meteorological data during 1960 to 2019 of 3 national meteorological stations in the city of Suining, the variation characteristics of sunshine duration and the influencing factors are analyzed by using the linear trend, wavelet analysis, Mann-Kendall test, IDW spatial interpolation and correlation analysis methods. The results indicate that the annual and seasonal variation of sunshine duration in Suining showed a decreasing trend, and the annual variation showed a significant decreasing trend, with the decrease amplitude in summer being the largest in the four seasons, which greatly affects the decrease of annual sunshine duration. The year of 1988 was the time point of the abrupt reduction of sunshine duration. The sunshine duration of each month showed unimodal type, which peaked in August. The sunshine duration showed a spatial distribution characteristic of "less in the south and more in the north". The sunshine duration oscillates obviously on the time scale of 17— 23 years. In terms of influencing factors, the variation of sunshine duration was very significantly negatively correlated with total cloudage, precipitation days, and significantly negatively correlated with precipitation.