Scanning thermal imager use real-time temperature-controlled blackbody to obtain the optimal corrected output. Using detectors in scanning blackbody to get feedback and forming closed-loop control systems are currently applied in correcting blackbody temperature closed-loop control. The period of the scanning feedback output of the detector is 20ms,which makes the bandwidth of the temperature control system limited,and the response lags. When the scene radiation changes drastically,the image correction output deviates,which affects the overall performance of the thermal imager. In order to solve this problem,the thermal platinum resistance temperature measurement is used as the feedback signal to realize the blackbody temperature control and increase the bandwidth. Through the actual multiple scene comparison tests,it is verified that the correction output of the thermal imager is more adaptable to the scene.