The accuracy of the calibration coefficients of the ground-based thermal-infrared radiometer CE312 is one of the most important factors affecting the calibration of the thermal-infrared remote sensors. The theory of two calibration methods which calculate the bandpass radiance and spectral radiance respectively is introduced. The calibration of the CE312-1b is conducted with the blackbody in the laboratory, the accuracy and influence factors of the results are conducted by the MODIS data combined with in situ measurements data at Qinghai Lake in Aug 2010. The results show that calibration coefficients of thermal-infrared field radiometer CE312 calculated by the bandpass radiance method has better performance in the accuracy and applicability than the spectral radiance method.