Abstract: 【Objective】 The analysis of runoff evolution law and its causes of Heihe River basin,and the basis for the optimal allocation of regional water resources,has important guiding significance for the optimal allocation of water resources and ecological environmental protection.【Method】 In this paper,MK test method,Morlet wavelet function method and cumulative slope change rate comparison method based on the change principle of hydrothermal conditions are used to analyze the multi-time scale complex structure of runoff evolution of Yingluoxia River in the upper reaches of Heihe River; taking the abrupt change year of runoff as the turning point segmentation sequence,the influence of climatic factors and human activities on runoff change is quantified.【Result】 The turning point of annual runoff was in 2005,and the annual runoff showed a significant increasing trend after the turning point. The first major cycle of runoff change is 24years,and the latest wet season is 2009～2018. The contribution rate of climate change to runoff change in the watershed is 70. 2%,and the contribution rate of human activities is 29. 8%.【Conclusion】 The situation of high and low runoff in Yingluoxia may change after 2019. Climate change is the main factor of runoff increase. The research conclusions can provide theoretical support for the evolution law of runoff and the optimal allocation of water resources.