Wide Area Power System Stabilizer (WAPSS) plays good damping effect on low frequency oscillation of power system. Meanwhile, coordinated optimization method of WAPSS parameters can avoid weakening damping of other oscillation modes when improving damping of one mode. In this paper, a two-stage coordination optimization method of WAPSS parameters is proposed. At the first stage, WAPSS lead-lag link parameters are designed based on the residual phase compensation principle. At the second stage, the optimized lead-lag link parameters are substituted into the WAPSS transfer function to reduce the decision variables, and then WAPSS gain parameter is optimized by improved Teaching-Learning-Based Optimization (TLBO) algorithm based on elitist strategy to improve the damping of the low frequency oscillation and near-imaginary axis modes which are multi-objective optimization. A two-stage coordinated optimization method of WAPSS lead-lag link and gain parameters can improve the system damping while reducing the optimization time. Finally, the simulation results show that the proposed method is correct and effective. This work is supported by National Natural Science Foundation of China (No. 51722701 and No. 51507056).