Abstract: This invention relates to a device for dividing and shifting television picture and its operating method, which comprises a Set Top Box and a controller both connected to a television; the Set Top Box capably converts input analog video signal to the television into output digital video signal to display video picture capably divided into a contracted picture and a controlled picture on the screen, and once the television is switched on, the television screen is always displayed said contracted picture and said controlled picture simultaneously; and the controller have a controlling key used to divide and shift TV picture, when said controlling key is pushed the video picture is displayed into full size on the television screen.