Abstract: In order to improve the grid-connected active power（GCAP） response speed of Virtual Synchronous Generator（VSG） under weak power grid, an optimization strategy of GCAP dynamic response for VSG based on the virtual negative impedance combined with the active power transient damping control algorithm is proposed in this paper. The optimization strategy firstly uses the virtual negative impedance control link to reduce the VSG equivalent output impedance as well as the GCAP dynamic response time of VSG. Then, the transient damping of VSG and the inhibition ability of GCAP dynamic oscillation are enhanced by the active power transient damping control link. In addition, the Matlab/Simulink simulation software is used to study the GCAP dynamic response performance of VSG in the condition of active power command step, and the experimental test platform of VSG grid-connected system is established. Finally, the simulation and experimental results verify the feasibility and superiority of the proposed strategy in improving the GCAP dynamic response characteristics of VSG under a weak grid.