Abstract: The twisted nematic liquid crystal can be regarded as a congruence of multilayer birefringent wafers, and the optical axes of the adjacent wafers rotate consecutively a small degree. A reflective model of the linear polarized light in the twisted nematic liquid crystal is proposed. A mode which describing the light reflectance in this liquid crystal is presented to conveniently discuss the propagation of the transmitted wave through a liquid crystal. The method of the correct adding of the electronic field is used to investigate the light propagation property in the twisted nematic liquid crystal. The analog computation shows that if the linear polarized light is vertically emitted into the liquid crystal, the intensity of transmitted light depends on both the wavelength of light and the structure of this liquid crystal. The experimental results show that the intensity of the transmitted wave is different at different voltage. In other words, the intensity of the transmitted wave with different wavelength is related with the structure of liquid crystal.