This article applies digital image processing techniques to the research for the algorithm of peep-temperature-field of flame image. Embarking on the factors which produce errors, the traditional bicolorimetric temperature measurement method is obtained proofreading. Then this algorithm is applied to the research on establishment of the temperature fields for gas combustion flame image in the small experiment table as well as radiative image in blast furnace raceway in some steel corporation. By the laboratory research we obtain that coefficient of correction equals to 33.4 and error value between the measured temperature and calculated temperature is in the scope of 5.0%. The result shows that the temperature fields of gas combustion flame image and those of radiative image in raceway reflect accurately the actual temperatures respectively as well as a series of changes for flame temperature information caused by varying working conditions. Therefore, it lays foundations for furnace operators to provide visualized image information and accurate temperature information.