Abstract: Based on the principle of dual phase shift control, the DC bias appearing in high frequency transformer’s ac current caused by the load transient is analyzed in dual active bridge converter(DAB). Without any extra hardware, such as block DC capacitor, the dual phase shifting digital control strategy based on the asymmetric phase is put forward. By using a single PI closed loop control system based on predictive current control, the control requirements for suppression of DC bias current not only can be met, but also many difficult problems such as PI control loop control parameters setting can be solved. The results of simulation and experiment show a good perform on the suppression of DC bias, and this methods further provide a good theoretical and experimental basis for the single-phase voltage source type dual active bridge DC-DC converter to realize the optimal control for storage energy system.