To solve the voltage sag problems of grid caused by sensitive load and improve the compensation efficiency of dynamic voltage restorer (DVR), an optimized comprehensive strategy is proposed. Firstly, the power flow and the maximum compensation time of DVR are analyzed using three basic compensation strategies. Then, the phase jump is corrected by pre-sag compensation. And, a transition curve, which involves the injected voltage phases of pre-sag strategy and minimum energy strategy, is used to transform pre-sag compensation to minimum energy compensation of DVR. As a result, the proposed strategy increases the supporting time for long voltage sags. The analytical study shows that the presented method significantly increases compensation time of DVR. The simulation results performed by Matlab/Simulink also confirm the effectiveness of the proposed method. This work is supported by National Natural Science Foundation of China (No.51477070).