Abstract: A particle swarm optimization(PSO) algorithm based on multi-model is proposed to overcome the problem of poor robustness in general PSO algorithm.The algorithm is applied to optimize the control parameters of PID and the complex adjustment of parameters in PID controller design is effectively avoided.Even in the case of model mismatch,the control system can maintain better control performance and have stronger robustness.Simulation experiments have been made on several typical controlled objects to demonstrate the practicality,effectiveness and(superiority) of the proposed optimization algorithm.