Abstract: H-bridge power module needs to be tested before it is put into use. The commonly used test method adopts back-to-back structure of two modules, which has low test equivalency and efficiency. Aiming at this problem, we propose a new type of H-bridge converter valve operational test device. The device adopts the back-to-back operation mode of H-bridge cascade converter valves, which is charged by two groups of DC power supply. Power exchange between valves can be realized by connecting reactances, meanwhile, multiple H-bridge modules can be tested simultaneously by using the devices. Moreover, the topology of the device is described in detail. The mathematical model of the device is established by using the input-output method, and the operation characteristics of the device are analyzed. The start-up strategy that can realize the quick charging of the sub module capacitance and the operation control strategy that can realize the steady-state voltage and current control of the device are proposed. The simulation results show that the test device can output voltages and currents according to the demand, and effectively simulate the operation state of H-bridge converter valve.