The occurrence of asymmetric faults in the grid can cause adverse effects such as a drop in the point of common coupling （PCC） and an increase in the output current amplitude of the power conversion system （PCS）， which may cause the PCS to cut out in severe cases. To address the above problems， this paper proposes a PCC voltage dynamic support strategy under asymmetric faults. First， the operating characteristics of PCS under asymmetric faults are analyzed， and the voltage support equation is obtained. Then the fault-ride-through operation area is divided according to the grid connection criteria， and the PCC voltage dynamic support scheme is designed based on the voltage support equation and the fault ride-through operation area， while the PCS output current amplitude is limited to further suppress the negative sequence voltage， ensuring the voltage support effect and sufficient capacity. Finally， the effectiveness of the proposed strategy is verified in Matlab/Simulink.