Abstract: Due to the large horizontal and vertical spatial span, as well as issues such as stepping motion and effective thermal radiation, it is difficult to measure the temperature during the phase transformation process of round bars in the cooling bed area, thus making it impossible to achieve precise control of the cooling process. Thus, this paper develops a surface temperature measurement system for monitoring the phase transformation process of round bars. The system dynamically captures bar targets using infrared temperature measurement images and visual detection algorithms. It is able to realize individual identification of bar temperatures in the cooling bed area through the dual-parameter measurement of bar position and temperature. In addition, the system can capture and record the initial axial temperature distribution of each round bar to evaluate the consistency of the through-bar temperature distribution, and can track the temperature evolution process throughout the phase transformation of each round bar one by one. It can provide reliable support for the traceability analysis of bar product quality issues and the development of new product varieties.