Radiation temperature measurement,as an important means to study the combustion characteristics of pyrotechnics such as infrared decoys,is often limited by the detector material and the temperature measurement range is narrow,which cannot meet the demand of temperature measurement of pyrotechnics with high combustion temperature.In order to solve the problem that the temperature measurement range of an infrared thermal phase detector is narrow.Firstly,the calibration theory of the radiation temperature measurement system is analyzed in this paper and the relationship between the gray scale response of a wide dynamic range detector pixel and the target radiance is established.Secondly,the maximum detectable temperature of the system at 250 μs integration time is increased from 140 ℃ to 1796.33 ℃ through the neutral density attenuation sheet with a preposition transmittance of 0.119 % set,while the maximum detectable temperature of the system at 500 μs integration time reaches 1233.81 ℃,and the high temperature measurement error above 450 ℃ within the integration time of 250 μs,500 μs,800 μs,1000 μs and 1500 μs is less than 0.5 %,achieving a good measurement accuracy.