The invention provides an automatic paper laying method in a slab double-sided stick decorative paper production line. The method is simple and high in work efficiency. An automatic paper laying mechanism with a front-back moving device, a lifting device, a paper sucking device and a paper storage rack is used, wherein the front-back moving device is movably arranged on a machine frame, the lifting device is arranged on the front-back moving device, and a suction cup is arranged on the lifting device. In the use process, the suction cup sucks decoration paper on the paper storage rack, gets close to the front end of the production line in the front and back direction, is moved forwards to the assembly line and then puts down the decorative paper; the front-back moving device retreats, the suction cup sucks the decorative paper on the paper storage rack, gets away from the rear end of the protection line in the front and back direction, is moved forwards to the assembly line and then puts down the decorative paper. The upper surface of the decorative paper serves as the lower surface of the decorative paper on a paper stack.