Abstract: With the continuous improvement of the river flood control system in China, the role of joint flood management of reservoirs group is gradually becoming apparent, and the rapid development of computer science and technology makes the optimal operation schemes of reservoirs more diverse. According to the structural characteristics of the mixed reservoir group, considering the flood control capacity of the reservoir group, the safe discharge of the downstream river channel and the flood routing of the river channel, this paper establishes a mixed reservoir joint operation model with the goal of maximum peak reduction, and solves through an improved particle swarm optimization algorithm. Taking the GuiwuShanhong- Longwangshan Reservoirs flood regulation system in Xuyi County of Huai'an City of Jiangsu Province as an example, taking the 20-year and the 50-year return period design flood as the input conditions, the calculation results show that the maximum discharge of Longwangshan Reservoir after optimized regulations is 10.4% and 13.5% lower than that of the regulation scheduling, and the optimized regulation reduces the maximum occupied storage capacity of the reservoir to a certain extent, which is more conducive to the safety operation of the reservoir itself.