With the gradual increase of the rate of distributed energy penetration, the moment of inertia in the power system is relatively reduced. This seriously affects the safe and stable operation of the system. The Virtual Synchronous Generator (VSG) has attracted attention because of the related characteristics of synchronous generators. Coupling in the transmission power of the VSG actual output port point to the grid-connected point causes the VSG power control to generate steady-state error and dynamic oscillation, thereby causing a change in the droop characteristic. Based on the analysis of the dynamic and static power coupling mechanism, this paper proposes a power decoupling strategy based on virtual steady-state synchronous negative impedance, which better eliminates the coupling effect between power loops. The global state space small-signal model based on the new VSG power decoupling strategy is established, and the effectiveness of the decoupling strategy is proved. Finally, the VSG experimental platform based on the decoupling strategy is built. The experimental results verify the effectiveness of the strategy, and show the elimination of the coupling between power loops, and the enhancement of the dynamic and static response of VSG active power and reactive power. This work is supported by Science and Technology Project of the Headquarter of State Grid Corporation of China (No. SGTYHT/18-JS-206).