Power switch apparatus of universal serial bus device

A power switch apparatus of universal serial bus device for protecting the universal serial bus device from electrical interference between a bus power mode of importing electric power via a universal serial bus port of the universal serial bus device and an external power mode of importing electric power via a direct current socket of the universal serial bus device, which comprises:

• a slide switch encased in the universal serial bus device for selecting the universal serial bus device to be operated in either the bus power mode or the external power mode by shifting a control rod of the slide switch;
• a cover having a window mounted on the universal serial bus device and;
• a socket door movably fitting in an inner face of the cover for selectively shielding or exposing the cover by confining a knob protruding from an outer side of the socket door between a first extreme point and a second extreme point of the window, the socket door further having at least a flange for shifting the control rod by guidance of the knob at either a first position to enable the direct current socket and suspends the universal serial bus port or a second position to enable the universal serial bus port and suspends the direct current socket, thereby prevent the electrical interference from happening.