Abstract: Large area surface temperature measurement technology is of great significance in the field of wind tunnel temperature measurement. In order to meet the needs of measurement for higher surface temperature, it is urgent to develop new temperature sensing materials and new temperature measurement technology. Temperature measurement based on the fluorescence intensity ratio of the thermal coupling energy levels of rare earth ions is a new temperature measurement technology. In this work, a temperature sensitive luminescent material (YAG:Dy) was synthesized. The corresponding relationship between the temperature and the ratio of emission intensity of the thermal coupling energy levels of rare earth Dy³⁺ ions (⁴F_9/2→⁶H_15/2, ⁴I_15/2→⁶H_15/2) was investigated in the temperature range from 50 to 1000 ℃. Based on this material, a comparative experiment of two temperature measurements that the fluorescence intensity ratio measurement and the infrared thermometer is carried out. It is shown that the measurement results of the two technologies have a high degree of agreement, which proves that the temperature sensitive luminescent material (YAG:Dy) can be used for temperature measurement in the range of 50–1000 ℃.