According to an embodiment of the present invention, a manufacturing method of a liquid crystal display device comprises the following steps of: preparing a lower display plate in which a pixel electrode is formed and onto which a lower alignment film including reactive mesogen is applied; preparing an upper display plate in which a common electrode is formed and onto which an upper alignment film including reactive mesogen is applied; injecting and coupling a liquid crystal between the upper display plate and the upper display plate to form a display plate assembly; applying a voltage to the display plate assembly and primarily irradiating an ultraviolet ray of a 310 nm to 380 nm wavelength to pretilt the liquid crystal; and secondarily irradiating an ultraviolet ray of 300 nm to 360 nm wavelength to the display plate assembly to eliminate remaining reactive mesogen.
