An external display system for displaying data of an input operating interface comprises: a computer module comprising a host, a display and a keyboard; a mouse module comprising a sensor unit, a first USB transmission interface unit, a control unit and a switch unit; an external display module comprising a second USB transmission interface unit, a microprocessor, a storage unit and a display unit. Upon receiving the triggering signal, the mouse module sends a signal to the microprocessor via the host. The microprocessor retrieves the status non-video data or the setting non-video data, generates and displays a status video data and/or a setting video data on the display unit. Or the microprocessor retrieves and transfers the setting non-video data to the host, and the host generates and transfers the setting video data to the display.