Today, fire always causes great damage to people and their properties, and the risk of fireoften comes suddenly and unconsciously. Because of lacking of efficient fire-fighting facilities, thefiremen in the rescue of the property and lives of the people got trouble in the fire environment. Sothe fire system equipments were hardly needed and the performance must meet the practical use. Inour paper, we design a system which is based on received signal strength indicator (RSSI) in theZigBee wireless sensor network (WSN) positioning system. This is a very good demonstrationsystem for the fire system. The system for firefighters could reflect the location of the firefightersand the information of current fire-site. The commanding officers outside the scene of the fire canalso learn this information. Finally, we test our system in real indoor environment, and ourpositioning system shows good stability and the positioning accuracy is improved.