The utility model relates to an electric-car regenerative break energy storage device and belongs to the technical field of electric storage. The electric-car regenerative break energy storage device comprises a super capacity energy-storage module (1), a bi-direction half-bridge direct current (DC)/DC converter (2), a buffer circuit (3), a high-voltage current-limiting fuse device (4), a single-chip (5), a voltage converter (6), a current sensor (7), a temperature sensor (8), a voltage sensor (9) and a seven-segment digital tube display module (10). The electric-car regenerative break energy storage device has the advantages that the single-chip is used for switchover of circuits of Boost-Buck chopping operation modes and is connected to the two ends of a motor bus in parallel according to polar requirement, frequent storage and release of breaking energy can be achieved only by using physical properties of the super capacity energy-storage module, and the installation is simple. Voltage-limiting and current-limiting protective measures are provided, voltage ripples can be suppressed effectively, a regenerative break system and a vehicle accelerating property can be improved and service life of a storage battery is prolonged.