An improved corridor constraint and IPSO-DPSA algorithm were proposed to solve the problem of morphological distortion of the dispatching line in the reservoir operation optimization process. Based on the hybrid algorithm of particle swarm optimization and dynamic programming successive approximation, this method optimizes the evolution process by introducing improved corridor constraints, special individual evolution mode, external elite set strategy, making the solution set as close as possible to the Pareto-optimal front of the multi-objective problem. The case study of the multi-objective optimization problem of the scheduling graph of the Chitan Reservoir shows that the algorithm can effectively control the morphological distortion of the dispatching line in the optimization process, and has good optimization performance.