For micro-grid voltage sag problem,the paper researched on a new dynamic voltage restorer(DVR) system which based on super capacitor energy storage.This paper introduced super capacitor energy storage and used the ability of charging and storing electric charge of super capacitor effectively,super capacitor enables dynamic voltage restorer provide a stable voltage quickly. In addition, the paper studyed control strategy of dynamic voltage restorer based super capacitor,used feedforward and feedback double-loop control strategy and led into capacitor current feedback.This improves the dynamic response speed and control accuracy of system.Because of the increased discharge power of DC power, the dynamic voltage restorer suit the micro-grid line whose voltage drops frequently. In addition, it has suitability for resistive load or inductive and resistive load. Simulation results verify the validity and correctness of theoretical analysis.