In the laser soldering process, real-time measurement of the solder joint temperature and adjustment of the output power of the semiconductor laser are crucial for ensuring welding quality. To avoid faults such as solder scorching, virtual soldering, and false soldering caused by excessive temperature measurement errors or slow measurement speeds, a high-precision IR radiation temperature measurement device is designed. First, the principles of IR radiation temperature measurement are introduced, and the design method of the IR radiation signal conversion circuit is explained. Second, the primary signal processing method used in this study, which is a Butterworth-type infinite impulse response filter, is introduced. Finally, the performance of the device is validated through experimental analysis. The experiments demonstrate that the IR radiation temperature measurement device designed in this study is suitable for non-contact measurement of solder joint temperature in laser soldering, with a maximum error of 2℃ within the test range of 70-260℃ in a standard blackbody furnace. During the laser soldering process, the highest temperature error is less than 0.6%, making it widely applicable to the field of laser soldering.