Portable power supply

The utility model discloses a portable power supply, and the power supply comprises a housing which is provided with a button, a charging interface, a discharging interface slot, and a discharge interface. The interior of the housing is provided with a central shaft. One end of the top of the central shaft is connected with the button, and the other end is sequentially connected with a battery, a reel for the winding of a wire, a spring structure, and a circuit board. The spring structure comprises a reelable spring piece. The interior of the housing is also provided with a tension ring and a tension direction converter. The other end of the tension direction converter is connected with a tension structure. The tension structure comprises a pedestal, a first spring, a pull rod, a pin, a spring pedestal, a second spring, and a pusher. The bottom of the pusher is provided with a card slot which is matched with the upper end of the pin. The power supply provided by the utility model is simple in structure, is easy to manufacture, can be used for the charging of digital products at any time, and guarantees that a user can be located in an environment of information safety.