According to the temperature-time curves of Liquid Crystal Display (LCD) module and the heater with different distance between LCD and heater (d), and with various pressures (p) respectively, the heat transfer mechanism based on LCD module was founded, showing contribution rate changes of heat conduction, heat covection and heat radiation during different periods of being heated. Factors affecting the efficiency of heat utilization for LCD modules were analyzed. Furthermore, solutions of water vapor fault for LCD modules during the heating process at low temperature were discussed.