The short circuit testing machine is designed based on the requirements of various battery short-circuit test standards. According to the standard requirements, the short-circuit device must meet the internal resistance range ≤ 5m Ω, so as to obtain the maximum short-circuit current required by the test; In addition, the circuit design of the short-circuit device must also be able to withstand the impact of high current. Therefore, we have selected industrial grade DC electromagnetic contactor, all copper terminal and internal copper plate diversion. The wide and thick copper plate can effectively improve the heat dissipation effect, make the high current short-circuit device safer, effectively reduce the loss of test equipment and ensure the accuracy of test data.