The phenomenon of light leakage may appear when a rugged LCD is operated in vibration environment.An effective method is proposed for analysis of the phenomenon.At first, a simplified rugged LCD model is used for making analysis to the finite element, and the optical property simulation software is used for calculating and comparing the transmittance of light in stationary state and vibrating state.Experiment is made to verify the effect, which explains the mechanism of white spot generation from the perspective of the transmittance changing of liquid crystal screen.In addition, the effects of different LCD modes and different thicknesses of rugged glass on the change of light transmittance in random vibration environment are also studied.The proposed method is helpful for improving the yield rate of rugged LCDs and reducing the production cost.