Abstract: Dual channels are currently the mainstream retail model. In this context, this paper proposes four supply chain operation models based on the contract types and service providers. That is, manufacturers provide services and sign wholesale price contracts with retailers ( model); retailers provide services and sign wholesale price contracts with manufacturers( model); manufacturers provide services and sign consignment contracts with retailers( model); retailers Provide services and sign a consignment contract with the manufacturers( model). This leads to the following three questions: (1) Which model has the highest service level and lowest retail price? (2) What is the profitability of manufacturers and retailers under the four models? (3) Considering the mutual game between manufacturers and retailers, what is the equilibrium mode in the market? At present, there is no document to answer the above three questions. In order to solve them, this paper constructs a dual-channel supply chain composed of manufacturers' online direct sales channels and retailers' offline channels. According to different contract types and service providers, four supply chain operation models are proposed. In each mode, a game model between the manufacturer and the retailer is constructed, and the optimal decision in each model is obtained. Then, a comparative analysis of the optimal decision-making under the four models is carried out to determine which mode has the highest service level, the lowest retailer price, and the largest profit level; at the same time, the equilibrium operation model in the market is determined. Our analysis shows that the key to the results depends on service cost-effectiveness and online channel market share. The research in this paper can provide theoretical guidance for business decision-making and improve the overall performance of the supply chain.

Key words: dual-channel supply chain, wholesale price contract, consignment contract, service