Abstract: The underground coal fire disaster is serious in China and continuous combustion of coalfield fire area poses great hazards. The traditional water injection method is unscientific with huge engineering quantity and low efficiency which resulting in plenty of water waste. Water injection technology in coalfield fire area needs to be developed in the direction of real-time data monitoring and automatic injection allocation. Intelligent injection technology is studied. Temperature parameter acquisition module, circuit control module and flow control valve are integrated in the intelligent injection distributor and placed on the ground for a long time. Combining with wireless communication technology and automatic adjustment algorithm, an intelligent injection process including intelligent injection distributor, intelligent measurement control and charging integrated instrument and ground communication control host was developed. The monitor system is developed to adjust the operation time of water injection and temperature measurement process remotely to control the water injection process The hierarchical control of water injection flow of 2L/s, 1L/s and 0.5L/s is realized. Sandaoba coalfield fire area test in Xinjiang Province shows that the intelligent grading water injection technology can provide technical support for "intelligent" fire extinguishing in coal fire area.