Non-isolated bi-directional DC/DC converter is wildly used in hybrid DC power supply system.Based on supercapacitor- battery hybrid energy storage system,using state-space averaging approach,a small single mode of a novel interleaved parallel bidirectional DC/DC Converter operating in Boost mode is built,and an AC small-signal state equation and an equivalent circuit under the phase inductance current continuous mode( CCM mode) are obtained.The open-loop transfer functions of the circuit are presented. The result shows that the slope of low frequency band is 0dB/dec and have errorSofSstability; the crossingSfrequency of intermediate frequency band is to high lead to big overtop ;the slope of high frequency band is -20dB/dec and the robustness against disturbance is poor. Based on the result,the feedback loop compensation design is given to optimization design of the controller,improving system stability and dynamic response speed.Finally,the model is built using Matlab.The simulation analysis shows that the output voltage can stable in 10ms and fluctuation is under 1.5% when input voltage with load changed,it can used to electricSvehicle power system.