A method of bonding substrates includes steps as follows. Providing a curved glass substrate and a flexible light-transmissive film; moving a roller to press the flexible light-transmissive film onto the curved glass substrate so that the flexible light-transmissive film matches a curvature of the curved glass substrate to gradually fit and bond onto the curved glass substrate; sensing the attaching level of at least one local area of the flexible light-transmissive film bonded on the curved glass substrate; and adjusting a press force exerted by the roller to the local area of the flexible light-transmissive film according to the attaching level during the flexible light-transmissive film is bonded onto the curved glass substrate.