In this paper, a new multi-objective salp swarm optimization algorithm is proposed, which is combined with equality constraint modification technology and feasible solution dominant constraint processing technology to solve the highly constrained environmental economic optimization dispatch problem of power system. A Gauss sampling strategy and a mutation operator is adopted to enhance the optimization performance of the suggested algorithm; A non-dominated sorting method based on improved dynamic crowding distance is used to obtain a uniformly distributed Pareto-optimal front; A fuzzy set theory is applied to provide the best compromise solution for decision makers. Simulations are carried out on the IEEE 30-bus 6-unit standard test system and compared with other optimization algorithms. The results show that the proposed algorithm has better optimization effect in solving power system environmental economic dispatch problem.