A system for splitting a display zone of a screen is installed in an electronic device having a screen, and includes a detecting module for detecting screen pixels. A splitting processor receives a splitting instruction containing a splitting number n, and splits the display zone into a main display region and a number (n−1) of extension display regions. A total number of width pixels of adjacent ones of the main and extension display regions from left to right of the display zone equals the number of width pixels of the screen. A total number of height pixels of adjacent ones of the main and extension display regions from top to bottom of the display zone equals the number of height pixels of the screen. A display module displays two or more operating interfaces, files, and/or pages of at least one application in the main and extension display regions, respectively.