In order to prevent fire of building lighting ， the fire code has made clear provisions on the fire prevention and insulation of building lighting. However， due to the lack of unified heat preservation and heat dissipation measures， there are different heat preservation and heat dissipation measures in electrical fire detection. This paper discusses the general fire prevention problems of lighting system， and probes into the technical measures of heat preservation and heat dissipation. In case of fire， smoke and flame will penetrate the holes left by the ceiling when installing lighting devices， enter the ceiling and extend to the upper part of the ceiling， so as to expand the fire. In order to prevent damage to the entire ceiling refractory， and make the lamps achieve the purpose of heat preservation and thermal dust removal， it can be solved by using the anti- fire cap and fireproof mat made of fire retardant coating. This method can also be used for fire protection and thermal insulation of various junction boxes to solve the shortage of lamps， filling switches and connectors.