A digital media controller is provided. The digital media controller includes a video input interface configured for connecting to a host computer; a video output interface configured for connecting a display; a storage card interface configured for receiving a storage card which is used to store media files; a media processing unit configured for decoding the media files to video signals and audio signals; a switch unit connected between the video input interface and the video output interface, and the media processing unit, and controlled by the processor; the processor being configured to control the switch unit to connect a signal channel between the video input interface and the video output interface, and between the media processing unit and the video output interface according to a predetermined control rule.