Abstract: For shortages of traditional Buck-Boost converters such as limited output voltage, poor stability, low voltage gain and so on, a novel bidirectional DC-DC converter was designed which used Z-source network to connect DC input power and load. Working process of the novel converter was analyzed during power forward transmission and power reversed transmission. The experimental results show that the novel converter not only realizes bidirectional power transmission, but also realizes voltage lifting and falling under power forward transmission mode or the reversed one. In addition, the novel converter has more stable output voltage and higher voltage gain than traditional Buck-Boost converter.