The electrohydraulic servo system of injection molding machine is a timedelay,nonlinear and complex system,using conventional PID control method is difficult to achieve desired control effect.In order to obtain good control effect,a hybrid particle swarm optimization (HPSO) method was proposed to optimize PID controller parameters.The simulated annealing algorithm was introduced into the particle swarm optimization,so the optimal parameters of PID controller could be found out more quickly and accurately.The control model of the electrohydraulic servo system was established by using MATLAB simulation software,and the HPSO algorithm was compared with particle swarm optimization algorithm and genetic algorithm.The simulation results show that the PID controller optimized by HPSO algorithm has fast convergence speed,high accuracy and strong robustness,which significantly improves the control performance of the system.