In order to flexible deployment of internal energy in the multi-energy microgrid, and reduce its carbon emission pressure, this paper proposes a multi-objective optimal dispatching method for multi-energy microgrid based on improved particle swarm optimization (PSO) algorithm. A cold-heat-electric multi-energy microgrid model is established. Based on this model, the coupling mechanism between various energy sources is analyzed and the mathematical models of system equipment are established. Secondly, with the goal of minimizing the operating cost and environmental cost of the microgrid, the multi-objective optimal dispatching model is constructed. An improved PSO algorithm is proposed. This algorithm can accelerate convergence speed and improve optimization performance by adjusting the iteration rules of the main parameters and adopting the adaptive particle optimization strategy. Simulation results verify that compared with the conventional methods, the proposed multi-objective optimal dispatching method based on improved PSO algorithm can effectively accelerate algorithm convergence speed, reduce the overall cost of the system, and balance its operational economy and environmental friendliness.