Liquid crystal display is the most valuable and universal produce of the electric monitor presently. Due to the non-luminant display device, it must use the light source of the backlight module to reach display effect . In backlight module field , it is focus on the even distribution of the light source and the perfect appearance without any defect occurrence. Besides, the existence of film waving will cause the bad phenomenon .To improve and avoid the defect occurrence,through the workable analysis experiment can find the real element progressively . In the experiment , we will focus on the characteristic of the film material and each material¡¦s dimension which analyze by BM-7 and Nieo LCD analyzer,etc. According to angle orientation.From the result,we can realize that the stronger structure material and larger heat capacity of Diffusion Film, will decrease the expand and shrink for temperature , and film waving caused by temperature changing, which may resolve the film waving effectively.