From the relationship between food product safety and quality， we see separate attributes because the former is a special form of the latter and has obvious attributes of public goods. Here based on the common attributes of food product safety and product quality， we adopt function tool to construct a logical expression between them under some mapping rules. Then， food safety is incorporated into the existing theoretical framework of economic analysis of food product quality. To optimize the decision-making behavior of enterprises， the equilibrium equation of food safety is derived from the theoretical model setting. Meanwhile， in combination with quality management modes of enterprises， we discuss the definition and quantification of the product quality from two dimensions. Finally， we divide the total effect of cost change into structural and behavioral components and describe the mechanisms of the impact of various factors on food safety and on costs， where the improved effect on the cost of production comes from the contribution of food safety.