Runoff variation and cycle characteristics of small watershed analysis have important practical implications for water conservancy construction of small watershed, water resources development and utilization. Based on the natural runoff series of Diaoshuiyan gully in Wujiang River from 1961 to 2014, the annual distribution, trend characteristics, catastrophe characteristics and periodic characteristics of annual runoff series are analyzed and studied by Gini coefficient, cumulative anomaly method, Mann-Kendall method and Morlet wavelet analysis method.. The results show that most of the annual runoff distribution in the Diaoshuiyan gully is relatively reasonable, and some of the annual runoff distribution is quite different; the annual runoff of the Diaoshuiyan gully shows no significant decrease; the annual runoff changes frequently, with sudden changes occurring mostly in 1992-1998; the annual runoff has obvious periodic characteristics, the first main cycle is 23 years, and the second cycle is 17 years and 6 years. The research results can provide a basis for the development and utilization of water resources in small watershed.