A method for manufacturing an optical film includes providing a molding machine. The molding machine includes a hopper, a first cylindrical roller, a second cylindrical roller, and a UV light source. The first and second cylindrical rollers are located at two opposite sides of a narrow outlet of the hopper and positioned at substantially a same height just below the narrow outlet. Thereafter, a UV-curable material is provided into the hopper, and flows out from the narrow outlet of the hopper. The UV light source is turned on toward the UV-curable material. Furthermore, the first and second cylindrical rollers are rotated to directly press the UV-curable material when the UV-curable material is cured.