A heat dissipation optimization method was proposed for the backlight module of the high-brightness rugged display by improving interface materials，designing low thermal resistance heat dissipation path and optimizing parameters of the cooling grid， through the analysis of the internal heat dissipation environment of the rugged display. A certain type of ruggedized display was taken as the research object， and the heat dissipation performance between the original design and optimized design was compared.The results showed that the working temperature of the LED on the backlight module was greatly reduced after applying the proposed heat dissipation method.