This paper proposes the designing of regional compensation Dynamic Voltage Restorer(DVR), and the topology of main circuit, the detection algorithm for voltage sag, the calculation method of reference voltage and pulse modulation method are introduced. Based on the different load types of the target substation and the sensitivity to voltage sags, the principle of the selection location of compensation line for regional compensation DVR is proposed, and the realization of substation line selection method is illustrated by taking a substation as an example. The compensation effect of the DVR under different fault types are simulated, and the validity and rationality of the designing are verified.