A LGP plate-to-plate manufacturing includes the steps of: preparing an optical substrate with a first surface and a second surface; mechanically extruding a first integrated microstructure on the first surface of the optical substrate; coating an optical layer on the first or second surface of the optical substrate; and curing the optical layer to directly form a second microstructure on the first or second surface of the optical substrate; wherein the first integrated microstructure and the second microstructure are separately formed at a time to provide a light guide plate structure. In an embodiment, an additional optical layer is provided on the optical substrate.