Affected by temperature, light intensity and other factors, the stand-alone PV system has disadvantages of intermittence and time-sharing. However, the energy storage system "peak" feature can make up for the shortcomings of the photovoltaic system. By introducing the battery energy storage system, the DC bus voltage can be stabilized at a constant value and shortcomings of the stand-alone PV systems can be make up. This paperSrealizesSbidirectional flowSenergy through theSbi-directional Buck/Boost circuit. Complementary PWM control method was adopted to realize the storage battery charging and discharging of smooth switch. Voltage and current double closed-loop control method was applied to suppress the DC bus voltage fluctuations. Dual bi-directional Buck / Boost converterScan not only reduce the weight of the inductor and the size of the equipment, but also can reduce the size of the ripple voltage, at the same time increase the capacity of the equipment. Finally the experiment platform was set up on the basis of laboratory equipment, and verify the correctness of the control strategy.