The current domestic exterior insulation system fire incidents are frequent. The study of exterior insulation system fire performance gets more and more relevant national authorities and insiders' attention. Based on two sides wall exterior insulation system as the research object, fire prevention experimental research method of insulation system and the insulation system temperature spread rule are expounded. Reveals the insulation system burning speed and scope of the fire from spreading under the action of the fire. The temperature and temperature field change regularity and insulation system of damaged situation after combustion are compared, and structural measures to improve the insulation system fire performance role is drawn.