The virtual synchronous generator (VSG) technology mimics the operating mechanism of synchronous generators, enabling distributed generation to provide inertia to the grid and improve system stability. When the VSG is connected to the low-voltage microgrid, there is a coupling between the active and reactive power of the output of the VSG due to the influence of the impedance ratio of the line impedance. In addition, the power coupling will be increased if the VSG power angle is too large, and the difficulty of decoupling will be increased. In this paper, the VSG power coupling mechanism is analyzed to discover that the power coupling will cause the dynamic oscillation of the VSG output power and the steady-state error of the reactive power. On this basis, adaptive virtual impedance decoupling strategy is proposed to decoupling, and uses fuzzy control to estimate VSG power angle. Finally, the VSG grid-connected model is built by MATLAB/Simulink to verify the suppression of the VSG power coupling.