| In order to further improve the temperature uniformity of the substrate in the evaporation coating machine, this paper takes the evaporation coating machine as the research object to model. COMSOL finite element software is used to simulate the temperature field of substrate heater in vacuum environment, and PID algorithm is coupled for temperature control, which reveals the temperature distribution law of substrate. On this basis, the influencing factors of substrate temperature uniformity are further studied, and the heating system is optimized by Nelder-Mead simplex method. The results show that when the distance between the top heating wire and the side heating wire is 1∶1. 23, the heating distance is 440 mm, and the reflection distance is 3. 56 mm, the maximum temperature difference on the substrate surface is reduced from 16. 5 ℃ to 9. 9 ℃ compared with that before optimization, and the temperature uniformity is improved. Finally, combined with the analysis of measured data, it shows that the error between simulation results and measured data is 6%, which verifies the effectiveness of optimization. |