At present, LCL filters have been widely used in the field of power electronic devices due to their low cost, simple structure, and wide applicability. However, when the frequency reaches the resonance point of the LCL filter, its frequency response characteristics will exhibit resonance peaks, which may cause system instability. In order to weaken this resonance peak, if the traditional proportional integral (PI) control strategy is adopted, its anti-interference performance is not outstanding, and it is difficult to achieve precise tracking control of sine signals without steady-state errors. Therefore, this article proposes an optimized quasi proportional resonance (QPR) controller strategy. This strategy has been improved on the basis of the original QPR control, incorporating a first-order high pass filter. This not only effectively handles harmonic disturbances, allowing the grid connected inverter to quickly adapt to grid fluctuations, but also effectively suppresses the adverse effects of grid voltage on grid connected current. We conducted simulation experiments in the MATLAB Simulink environment. The final experimental results show that this quasi-PR controller exhibits excellent anti-interference ability.