Mode control strategy and control structure of micro-grid in grid connected and islanded operation are different, when micro grid switch, due to two mode controller status does not match, the output of the controller will jump and produce larger transient shock. Therefore, according to the master-slave control structure of micro grid in grid connected mode and island mode and mutual switch, this paper presents a method of PQ control and based on improved droop of the V/F control combination, by adjusting the adaptive droop coefficient and the output of the controller state synchronization control for micro-grid smooth switching control strategy. In Matlab/ Simulink to build micro-grid model is simulated and analyzed. The simulation results verify the feasibility and effectiveness of the proposed control strategy. Results realize the micro-grid smooth switching, reduce the transient shock produced in the process of switching system effectively.