In the three-phase three-wire power system， the main control difficulty of the dynamic voltage restorer is the compensation of unbalanced voltage sag. Although the controller designed both in the positive and negative synchronous rotating frame can well compensate the unbalanced voltage sag， it has slow response because of the time delay in the state variable decomposition. To solve the problem， a hybrid digital multivariable state feedback controller is designed. When a sag is detected， a single digital multivariable state feedback controller designed both in the positive synchronous rotating frame is acted immediately to insure fast response. When the system has entered into steady state， the controller is switched to a double digital multivariable state feedback controller designed both in the positive and negative synchronous rotating frame seamlessly. When the sag die out is detected， the controller is switched back again. This control strategy ensures fast response and high steady accuracy as well. The feasibility of the proposed controller is verified through experiment results.