There is interaction between multiple power system stabilizers in the wide-area power grid, which affects the control effect of the whole system. Therefore, a coordinated design method of multi-objective wide area damping controller based on bat algorithm was proposed. This method made use of the population diversity of bat algorithm to keep the algorithm’s ability of continuous optimization in the iterative optimization process, which ensures that the algorithm has good convergence and accuracy. Taking the real part and damping ratio of the electromechanical oscillation mode as the objective function, the parameter optimization problem of the stabilizer of multi-machine power system was reduced to the multi-objective optimization problem with inequality constraint. The simulation results show that the proposed method can improve the eigenvalue distribution of the system’s weak electromechanical mode, effectively suppress the low frequency oscillation, and has good control effect and robustness.