Abstract: In order to study the variation rule of workpiece temperature in cylindrical transverse grinding process, 18CrNiMo7-6 gear steel was selected as workpiece material, and CBN grinding wheel was used as grinding tool. Infrared thermal imaging instrument was used to detect the grinding process temperature. Whether the calibration of emissivity value of thermal radiation is accurate is an important factor affecting infrared temperature measurement. In order to ensure the accurate measurement of temperature, a calibration scheme of thermal emissivity value with an additional air curtain device is proposed. The high-speed airflow generated by the air curtain is used to slow down the entry of external air into the heating furnace, prevent the oxidation of samples in the calibration process, and ensure the accuracy of the emissivity value calibrated under high temperature conditions. According to the test results, the influence of workpiece speed v_w, workpiece grinding depth per revolution f_a, grinding wheel granularity, grinding wheel diameter d_s and grinding width b on the temperature was analyzed. Compared with other parameters, the workpiece grinding depth per revolution f_a was the most significant factor affecting the temperature change, and the relevant empirical formula was obtained, with its own error of 9.27%. The measurement results were compared with those derived from the theory of moving heat source, Rayleigh distribution model and dry grinding heat distribution ratio model, and the deviation was 8.51%.