In order to optimize the position controller PID parameters of higher order nonlinear system, took the five order transfer function as an example, combining with the particle swarm optimization algorithm to achieve the parameter optimization. The PID parameter optimization principle of particle swarm optimization algorithm was designed. On the basis of the transfer function of the known system, the ZN method was used to solve the parameters of the system, Then used the particle swarm optimization algorithm to optimize the initial solution, and compare the dynamic performance of the system before and after the optimization, The results showed that the optimized high order nonlinear system had better dynamic performance, faster response speed, shorter time and better robustness.