The article proposes an improved topology structure with fault tolerance for switching fault, and analyzes the process of dual active bridge under SPS control under short-circuit switching fault. A DC isolation capacitor is connected in series on both sides of the transformer. Without affecting the normal operation of the circuit, this topology can tolerate a maximum of two switching faults, and has fault tolerance for open-circuit switching fault at the same time. Analyzed the transient process of the topology when a short-circuit switching fault occurs, provided the power transmission characteristics and soft switching range under the corresponding fault under SPS control, and finally built an experimental prototype and completed experimental verification. The experimental results verify that the proposed topology has fault-tolerant ability for switch tube short circuit faults.