Based on the analysis of runoff variation in the typical hydrological station of Zhangjiashan, the evolution law of runoff in Jinghe River Basin is revealed, and the future trend is predicted. The linear trend analysis, moving average method and Mann-Kendall test method were used to investigate the variation of runoff. The sequential cluster method and sliding t-test were applied to study the abruption of the runoff, and the R/S method was used to predict the future trend of runoff. The results showed that the distribution of annual runoff in Zhangjiashan Station was unevenly distributed, which was mainly concentrated in July and October, accounting for nearly 70% of the annual runoff. From interannual variation trend, dry year and wet year are alternating frequently, and mutation point is in around 1996. The flood season runoff was highly similar with the annual runoff, non-flood season runoff was relatively stable. The average runoff of Zhangjiashan Station from the 1950s to 1980s was relatively large, and from the 1990s to 2010s was less than the average of many years. Annual runoff, flood season runoff, and non-flood season runoff show a significant decrease trend, the Hurst index were greater than 0.5, which shows that there is a certain degree of continuity between the future and the current trend. The forecast will show a continuous decreasing trend in the future.