Abstract: The joint operation of the four-level cascade reservoirs(Wudongde, Baihetan, Xiluodu, Xiangjiaba) in the lower reaches of Jinsha River provides flood control security for Sichuan-Chongqing reach of Changjiang River.The evaluation on flood control effect can promote the utilization of flood resources in the basin.Based on the joint flood control operation scheme of the cascade reservoirs, an evaluation index system under the four criteria of flood control, power generation, ecology and shipping was established.Improved analytic hierarchy process and entropy weight method were adopted to construct an evaluation model of flood control operation effect of cascade reservoirs in Sichuan-Chongqing reach, and the flood control and benefits were comprehensively considered, so as to evaluate the flood control effect of cascade reservoirs with different inflow frequency and different water level of initial regulation.Comparing the effects of combined operation of Xiluodu-Xiangjiaba reservoirs and the four-level cascade reservoirs, we analyzed the comprehensive effects of Wudongde and Baihetan reservoirs on flood control operation and flood resource utilization in Sichuan-Chongqing reach.The results showed that:(1) the flood control efficiency coefficient of cascade reservoirs in the lower reaches of Jinsha River increased first and then decreased with the increase of the water level of initial regulation of the Wudongde-Baihetan reservoirs.(2) For the 20-year return period flood, 30-year return period flood, 50-year return period flood and 100-year return period flood, when the water level of Wudongde Reservoir and Baihetan Reservoir were regulated initially from(965 m, 795 m),(975 m, 790 m),(955 m, 790 m),(952 m, 795 m) respectively, the flood control efficiency coefficient of cascade reservoirs in the lower reaches of Jinsha River was the largest, and the joint flood control scheme of cascade reservoir was the best.(3) Since the Wudongde Reservoir and Baihetan Reservoir were built and put into operation, the utilization effect of flood resources in Sichuan-Chongqing reach has been improved.The research results can be used to evaluate the effect of flood control operation of multi-function and multi-protection object cascade reservoirs, and provide a basis for regional flood control operation decision.