The paper aims to optimize inventory and distribution based on shelf life, reduce loss of dairy product during cold chain, ensure quality of dairy product, reduce cost of enterprise, and increase consumer satisfaction. Considering the impact of shelf life on distribution, based on research of shelf life, the relationship between loss rate and shelf life of dairy product was established. Under the constraint of time window, with the minimum total cost as the goal, a distribution vehicle path optimization model without considering shelf life and a distribution vehicle path optimization model considering shelf life were constructed respectively, and the two models were solved by improved genetic algorithm. Comparing the optimal results of the two models, it was found that the total cost of distribution based on shelf life was reduced by 3.71% in a distribution cycle compared to the total cost of transportation without considering shelf life. To a certain extent, this research can reduce distribution costs and improve economic efficiency for logistics enterprises.