Abstract: PID controller’s performance completely depends on the combination of the control parameters，an improved particle swarm optimization（Crossbreed-PSO） is proposed in tuning and optimization of PID parameters in this paper，it adopts the crossbreeding mechanism in genetic algorithm，and using non-linear inertia weight reduction strategy to accelerate the optimize convergence and improve the search capabilities of particles.The algorithm is applied to optimize a second-order system PID control parameters，simulation results show that the improved PSO has a better performance than both the conventional particle swarm optimization and genetic algorithm，which means a well prospective.