A working mode soft-switching control strategy for switchable power module around power electronic transformer with access of electric vehicles is presented. Determine the number of switchable power modules operating in DC/DC, DC/AC, and blocking mode according to the predicted AC load power data. After determining that the switchable power module needs to switch the working mode, slowly reduce the output power of the switchable power module to 0 according to the ramp control and then the working mode is switched. This strategy can achieve a smooth change of the output power of the inverter, reduce the distortion of the load voltage and current at the switching time, prevent the breakdown of the filter inductor due to sudden changes in current, and improve the safety and reliability of the device. PSCAD simulation results show that the proposed control strategy are correct and feasible.