Abstract: The purchase, sale and inventory system of the cooperative e-commerce platform is an integrated information system to help the cooperative manage the purchase, sale and inventory of goods. Often a core part of e-commerce operations, the purchasesales-inventory system can help cooperatives efficiently track inventory, orders, supply chains, customer information, and perform data analysis to optimize operations. The key functions of the purchase-sales-inventory system of the e-commerce platform are studied,and the specific design scheme of the key functions is given.