Dual active bridge (DAB) converters has been widely used because of its high efficiency, high power density and bidirectional energy flow. DAB converters are prone to cause magnetic imbalance due to factors such as circuit parameters and asymmetric driving signals, which would affect the normal and stable operation of the circuit. Therefore, a DC bias detection and control strategy for transformer windings is proposed. This strategy uses the sampling resistance and Δ-Σ modulation, which can convert the current into a 1-bit high-speed data stream, and a sampling resistor is placed at the H-bridge DC end. From this, the average value in the positive and negative half cycles of winding current can be obtained, and the DC component of winding current can be obtained by subtracting it. At the same time, a DC suppression method for DAB is designed, which adjusts the DC component of the H-bridge output voltage by designing a controller to tune the duty cycle of any bridge arm. Finally, the effectiveness of DC bias current detection and control strategies has been verified through Matlab simulation.