In view of problems such as harsh condition,high-cost and high-risk in experiments in the research of reactive power compensation for impact load,a TSC dynamic reactive power compensation hardware-in-the-loop simulation system based on QuaRC platform and DSP is proposed. According to working characteristics of typical impact load,spot-welders,experimental subject is established in the simulation environment,and a reactive power compensation strategy is selected and implemented in the DSP.Simulation result conforming with actual conditions,the reasonability of the design of the system is verified.