In order to improve the reliability and stability of data transmission of the temperature field monitoring system of blast furnace hearth, and reduce the construction cost and maintenance cost, a wireless temperature monitoring system for blast furnaces based on wireless mesh network (WMN) is proposed. The data acquisition node is installed on the outside wall of the blast furnace hearth, which converts the analog signal of the thermocouple into digital signal, greatly shortens the transmission distance of the analog signal of the thermocouple and reduces the external interference. Then the temperature data is transmitted to the monitoring center through the mesh wireless network for analysis modeling and blast furnace hearth condition monitoring. The mesh wireless data transmission network is constructed based on IEEE80211, and based on the optimized linkstate routing protocol, a dualpath backup adaptive routing protocol and an adaptive handoff mechanism for primary and alternate routing are designed. Finally, based on OpenWRT opensource platform, a prototype system is built and installed in a blast furnace in Laiwu Iron and Steel works. The system has been put into a long period of continuous and stable operation, which can meet the needs of blast furnace hearth temperature field monitoring.