对大尺寸镜面镀膜,膜层的均匀性是影响膜层各项性能的重要因素。本文从理论出发,分析并选择了电阻丝热蒸发中点蒸发源的发射特性,合理地选择了点蒸发源的分布形式并与LAMOST的MA子镜建立数学模型形成一个蒸发沉积系统,编制程序计算了一些相关参数的变化对膜层厚度的均匀性的影响,设计出了一个简单的满足膜层最大厚度差小于5%的蒸发沉积系统。 Large-size mirror coating, film uniformity is an important factor affecting the performance of the film. Based on the theory, this paper analyzes and chooses the emission characteristic of mid-point evaporation source of resistance wire thermal evaporation, reasonably selects the distribution form of point evaporation source and builds a mathematical model with the MA sub-mirror of LAMOST to form an evaporation deposition system. The influence of the change of relevant parameters on the uniformity of film thickness was studied. A simple evaporation deposition system was designed to meet the requirement that the maximum thickness difference of film was less than 5%.