During the Stelmor air-cooling process, the temperature distribution has a significant impact on the wire loops’ final mechanical properties. The temperature distribution during air-cooling process is accurately solved by establishing three-dimensional model and numerical simulation. The heat transfer coefficient at the high dense region is much smaller than that of wire loops at the low dense region, and changes periodically over time, according to a Computational Fluid Dynamics (CFD) simulation method. It is also found that the heat transfer coefficient on the cross section of the wire loop is very different, with a difference of 70-100 Wm-2K-1. Finally, the finite difference method is used to calculate the mathematical model of the temperature distribution during the Stelmor air-cooling process. Comparing the results with the measurement data, the simulation results and measurement data match up well.