The utility model discloses an automobile brake generation energy storage device which comprises a brake master cylinder, a first oil way, an excitation winding contact, a storage battery, a generator stator, a generator rotor, a belt type brake belt, a stator winding, a rotor winding and a unilateral diode, wherein the first oil way is connected with the brake master cylinder and extends to an excitation winding, the excitation winding contact can be in contact connection with the first oil way, the generator stator penetrates through an automobile axle, the generator rotor is embedded into a brake drum, the belt type brake belt is arranged outside the generator rotor, the stator winding and the rotor winding are respectively arranged on the generator stator and the generator rotor, the excitation winding contact comprises three ends, the first end of the excitation winding contact is connected with an anode of the storage battery, the second end of the excitation winding contact is connected with the rotor winding which is connected with a cathode of the storage battery, the communication end of the excitation winding contact is communicated with the first oil way, the stator winding is connected with the anode and the cathode of the storage battery, a cathode of the unilateral diode is connected with the anode of the storage battery, and an anode of the unilateral diode is connected with the stator winding.