Aiming at the problem that the parameter selection of LCL grid-connected filter is complicated and how the parameter selection can directly affect thyine filtering effect, a parameter optimization strategy of LCL grid-connected inverter based on improved butterfly algorithm is put forward. Modeling in MATLAB simulation，the choice in port series damping resistance capacitance, maximizing and minimizing ripple current, harmonic attenuation, low power loss into as the optimization goal, and using the linear weighted method is changed into single objective model, using the entropy weight method to determine the weight coefficient of each target, finally using the improved butterfly algorithm for solving the objective function. Simulation results show that the improved butterfly algorithm, butterfly algorithm and genetic algorithm are compared with the function convergence curve, and the improved butterfly algorithm has outstanding optimization ability. Compared with traditional graphic method and genetic algorithm, the optimization strategy designed in this paper has stronger ability to reduce harmonic distortion rate and power loss under certain filtering conditions.