As an energy storage device, supercapacitors are widely used in the industrial field. In order to improve the output characteristics and extend the life of supercapacitor modules, a double voltage balancing technology for supercapacitor module is proposed in this paper, which is based on the requirements of the instantaneous power for future aerospace vehicles. The charge and discharge curves of supercapacitors under constant current conditions are measured to evaluate the characteristics of cells, which reveals their inconsistency. In the constant process of current charging, the double voltage balancing circuit uses the Buck-Boost converter circuit as the main circuit, and the switched resistance circuit acts as a backup circuit. The cell in the module achieves dynamic voltage balance during charging and reaches the rated voltage value at the end of charging without overcharging. The double voltage balancing circuit solves the problem of voltage imbalance caused by the inconsistency of monomers in the supercapacitor module.