Abstract: Because of the high order nonlinearity of the controlled object，the traditional PID ( Proportion Integration Differentiation) controller of parameter tuning method can easily lead to overshoot，oscillation and poor performance for the controller． To solve this problem，the parameters are optimized by using the ant lion algorithm which improves the moving step size of ants and ant lions． The optimal position of ant lion is selected to determine the controller parameters through its interaction relationship，and the algorithm is compared with the former ant lion algorithm and other optimization algorithms． The simulation results show that the PID controller based on the improved ant lion algorithm has better performance index． Compared with the former ant lion algorithm，genetic algorithm and particle swarm optimization，this algorithm has the advantages of higher system control accuracy and shorter response time，and its implementation is simpler． This method has superiority and validity in optimizing the parameters of PID controller，and provides a reference for the parameter optimization of PID controller．

Key words: proportion integration differentiation ( PID) controller, improved ant lion optimization algorithm, parameter optimization