In view of the input side power factor of single-phase dynamic voltage restorer (DVR) which is adopting the structure of AC - DC - AC is low, and harmonic content is high. This paper proposes a dynamic voltage restorer based on PWM chopper converter to compensate the voltage drop of load. The new topology without dc capacitor adopts PWM chopper control and simplifies the filter design. Harmonic content in the circuit is reduced, input side to achieve unity power factor. Single phase signal is constructed into two-phase signals to detective voltage. It is a high real-time by using instantaneous reactive power theory to detection and processing. Finally, we built MATLAB/Simulink simulation and experimental platform to verify the rationality and feasibility of the new structure.