The traditional wireless fire warning system based on GSM costs too much and the battery on the sensing terminal drains so quickly that it has been difficult to obtain large-scale application. However, with the rapid development of LPWAN, the system cost and the energy consumption of the sensing terminal have reduced greatly, and the development of the intelligent fire warning system has been promoted quickly. In this study, a wireless fire intelligent early warning system is designed based on big data. Through this system, not only can the fire be discovered in time, but also the location of the fire can be grasped in real time. At the same time, the linkage between multiple departments and the individual can be realized. The actual results show that the system has low communication cost and long life of battery. Moreover, the system effectively reduces the incidence of the urban fire, as well as it has improved the efficiency of fire rescue and the level of fire service, which has been widely promoted and applied.