Abstract: When large-scale floating roof oil tank is struck to fire by lightning, the seal ring between tank shell and floating deck will likely suffer from the fire. The current fire control facilities have two technical shortcomings in extinguishing this kind of fire. First, the alarm and control system, which are composed of field manual alarm, television monitor alarm, temperature sensing fiber alarm, can not send out the alarm accurately and timely; second, the fixed fire fighting equipment can not control the fire allover the tank body when oil level is high, and it is difficult to control fire at lower location of tank with foam to isolate air when oil level is lower. Therefore, the temperature sensing raster (or temperature sensing cable) is installed at the upper secondary seal of floating deck at 1 m's height and fixed with a bracket. The technique can effectively reduce the fire probability of tank in initial stage of fire. At the same time, the automatic fire monitor accompanied by monitoring system should be equipped to realize the monitoring of fire, detecting, fire fighting foam system starting and foam jetting with high sensitivity, reliability without fire blind area.