The invention discloses a visual field splitting tool used for fast reading training on a computer display screen. The display reading visual field splitter is made of plastics and is divided to three parts of a guide rail, a guide rail cover cap and splitting lines, wherein the guide rail is a thin hollow small pipe, and a straight groove is opened externally and is connected with an inner cavity; one end of the splitting line is expanded, the rest part is in a shape of a thin wire, the expanded end is placed in the guide rail, the thin wire-shaped part can pass through the straight groove from the inner cavity of the guide rail to cover the surface of the whole display screen, the position of the splitting line can be changed through sliding of the splitting line on the guide rail, and a role of splitting a visual field is played; and the guide rail cover cap can seal two ends of the guide rail to prevent the splitting lines from dropping out from the guide rail. The whole display reading visual field splitter is fixedly hung on the upper frame of the display in an adhesive mode through 3M glue, words on the computer display can be split according to the needed visual field size, and thus, fast reading training is facilitated, and the fast reading training effect is improved.