公差设计是产品设计中的重要组成部分。公差设计的优劣，对产品制造加工过程有直接影响。文章详细分析了产品公差设计的类型和过程及产品成本的各项因素，提出了公差—成本关系的基本模型，为基于成本最低的公差设计优化提供了基础理论依据。 Tolerance design is an important part of product design. The pros and cons of tolerance design, the product manufacturing process has a direct impact. This paper analyzes various factors of product tolerance design, process and product cost in detail, and puts forward the basic model of tolerance - cost relationship, which provides the basic theory basis for the design of tolerance design based on the lowest cost.