在假设厂商不会违约的前提下,建立了预订商品最优契约设计模型,讨论了定金优化选择问题.模型指出最优的定金ω-恰是厂商所售产品的利润,而主合同中规定客户购买该产品续交的资金ω恰为产品的成本c.最后指出,厂商向客户提供预订服务能够增加交易的总剩余,提高市场交易的福利. Under the assumption that the manufacturer will not default, the optimal contract design model of the reservation goods is established, and the optimal choice of deposit is discussed.The model points out that the optimal deposit is the profit of the products sold by manufacturers, while the main contract stipulates that the customers The purchase of the product continued to pay the funds ω is the cost of the product c. Finally, manufacturers offer to customers booking services to increase the total surplus of the transaction, improve the welfare of market transactions.