When the conventional human body model (HBM) is used for electro-static discharge (ESD) testing, the measured value of the power chip's antistatic ability deviates from the actual antistatic ability because of a parasitic effect, resulting in inferior products passing the HBM ESD test. This affects the improvement of the yield rate of power chip products. To this end, an improved HBM model is proposed, one which corrects the deviation of the electrostatic discharge current caused by parasitic parameters by introducing an RC parallel branch to meet the requirements of the electrostatic reliability test of the power chip. First, the mechanism of how static electricity causes damage to the power chip is described. Secondly, the influence of parasitic parameters on the ESD current is analyzed, and the limitations of the conventional HBM ESD test are elaborated. Then a new RC-HBM model is proposed, and the design basis of the RC parallel branch parameters is presented. Finally, batch experiments verify the accuracy and rationality of the HBM model proposed. This work is supported by the Science and Technology Project of State Grid Corporation of China (No. 5100-201946434A-0-0-00).