With the application of conditional free shipping policy becoming more and more extensive, there are more and more research theories for it. How to confirm free shipping conditions and shipping cost is becoming an important problem faced by e-commerce enterprises. Make example analysis for a series of solutions generated based on algorithm design and C# program design solving model and attain some conclusions: when the product price is within the psychological expectation range of consumers for this product, free shipping threshold is set at the boundary of all product price portfolios and situation of retailer profit jump will happen, in addition, the optimal free shipping threshold should be set around the mean value where the consumer expectation distributes. Of course, the pricing strategy of the optimal delivery service in enterprise is also affected by various factors; its forms are complicated and depend on the specific value of parameters.