Mathematical modeling can optimize dietary plans, but relevant research is scarce. This paper adopts the Analytic Hierarchy Process (AHP) and single-objective optimization model in mathematical modeling. Based on the “Chinese Food Composition Table”, an evaluation model is constructed, and This paper is presented from the perspective of food structure, energy, meal ratio, nutrients, and protein amino acids. Through Matlab programming, the diet is optimized to maximize the protein amino acid score and reduce costs. The results show that single optimization is prone to imbalance or high costs, while comprehensive optimization achieves both balanced nutrition and economy. This scheme provides a scientific basis for dietary optimization and promotes the development of healthy diets.