Abstract: This paper is going to analyze the main factors that affect the quality and efficiency of contact lens mold processing comprehensively based on the ultra-precision processing principles and high-precision requirements. The analysis and processing experiments show that the horizontal tool setting error is the most critical factor among them. In this process, a calculation model for the horizontal tool setting error based on the detection data is built by the combination of Nanotech 250 UPL and the precise detection principle of Zygo profiler. It is proved that this mathematical model can indicate and correct minor tool setting errors quickly and accurately based on the processing experiments on the molds of different contact lens models and sizes. With this mathematical model, the ultra-precision processing and testing of contact lens molds will be integrated effectively, and the quality and productivity of ultra-precision processing will be improved greatly.