Abstract: A new system, consisting of a fiber spectrometer and a monochrome CCD camera, was developed for online measurement of high-temperature fields, with which the actual emissivity and light intensity field of high-temperature radiation source can be measured simultaneously, and subsequently the high-temperature field can be obtained through calculation. The system was used to measure the temperature field of halogen lamp filament, a high-temperature glowing object, so as to obtain corresponding temperature fields at different voltages. Moreover, a comparison was made to the highest temperature respectively measured by the proposed method and the emission spectrometry. Results show that the relative deviation between above two methods is less than 5%. The proposed method can not only make up the deficiency of emission spectrometry that is unable to get corresponding temperature fields, but also avoid the temperature field measurement errors produced by colorimetric thermometer during instantaneous changes of emissivity and bandwidth of monochromatic wavelength, which therefore is proved to be an effective way for temperature field measurement.