Compared with the traditional buck circuit, the DC/DC converter based on Hbridge parallel connection can realize the bipolar output of voltage and redundancy control in case of failure, so it is very suitable for the situation that large power motor needs positive and negative rotation control. The structure of the parallel Hbridge DC/DC converter and the mode of dual pulse width modulation (PWM) were analyzed. To reduce the switching loss of Hbridge DC/DC converter under dual PWM, the passive soft switching technology was analyzed, and the performance difference between the RCD buffer circuit and the minimum stress buffer circuit was emphatically discussed. It was found that the minimum stress soft switching technology could obtain better soft switching performance. The minimum stress soft switch was used to simulate the parallel Hbridge DC/DC converter with dual PWM. Simulation results showed that the soft switching technology based on the minimum stress snubber circuit could be used in the parallel Hbridge DC/DC converter with dual PWM to achieve zero voltage switching on and zero current switching off.