String photovoltaic inverter is the core device of photovoltaic cluster grid-connected system. When multiple PV inverters operate in parallel, due to the interaction between the LCL filter and the system circuit, there is a large resonance risk in the grid-connected current. To solve this problem, a hierarchical cooperative control strategy for PV inverter cluster is proposed. In the first layer, the LCL filter capacitor is connected with virtual resistance + capacitor in parallel, which increases the main body damping of the inverter and suppresses the parallel resonance of the inverter. In the second layer, PCC voltage feed-forward is introduced to introduce equivalent virtual inductance to suppress the resonance between the photovoltaic cluster and the power grid. The simulation and experimental results show that the total harmonic distortion rate of the grid-connected current decreases from 9.43% to 0.17% and the degree of reduction reaches 98.2% after the parallel system of two series photovoltaic inverters is adopted, which verifies the correctness and feasibility of the strategy.