The invention discloses a multi-power-supply direct-current power supply device for a storage battery. The device comprises a main body and a buffering mechanism; a base is movably arranged at the bottom of the inner wall of the main body; a movable bolt is mounted on the inner side of the base; the buffering mechanism is mounted at the top of the base; a power supply is movably mounted at the topof the buffering mechanism; a limiting column is arranged on one side of the buffering mechanism; a movable mechanism is movably mounted at the top of the main body; a heat dissipation frame is movably connected to the inner wall of the main body; a heat dissipation mechanism is arranged inside the heat dissipation frame; a connecting plate is movably mounted at the top of the power supply; and amovable block is movably arranged below the connecting plate. The multi-power-supply direct-current power supply device for the storage battery is provided with the main body; and a fixed frame is fixedly connected with a groove, and when the device is used for a long time, the connection density between the fixed frame and the groove is increased, so that the groove cannot fall off from the fixed frame, the normal operation efficiency of parts is improved, and the situation that the device cannot be effectively operated for a long time is prevented.