The invention discloses an automatic attached screen layer separation device. A pair of linear guide rails are arranged in parallel on a work bench, a plate-shaped fixation seat for horizontally attaching and arranging an attached layer to be separated is connected on the linear guide rails in a sliding way; a slidable connection component cooperated with the linear guide rails is arranged on the bottom of the plate-shaped fixation seat, and the plate-shaped fixation seat is connected with the linear guide rails by the slidable connection component in a sliding way and can move along the linear guide rails. A division mechanism comprises a rotary winding roller, two division line guide poles and a division line, wherein the division line guide poles are symmetrically arranged on the middle segments of the linear guide rails and the height of the division line guide poles can be vertically adjusted; two rollers are arranged on the rotary winding rollers, the division line is drawn out from one roller and sequentially wound around the two division line guide poles and then rewound to the other roller, and the division line between the division line guide poles forms a division surface in parallel to the attached screen. The automatic attached screen layer separation device has features of accuracy in division, improved quality and production efficiency of products, and reduced cost.