Against the backdrop of the rapid development of cross-border e-commerce, pricing and inventory coordination are the core links in its supply chain management, which are of great significance for improving the efficiency of enterprise resource allocation, balancing the interests of the chain's internal entities, and enhancing the resilience of the supply chain. This study examines the impact of government policies on supply chain operations by analyzing cooperative and non-cooperative situations between overseas suppliers and domestic retailers. In the centralized decision-making model, overseas suppliers and in-country retailers fully cooperate in determining commodity prices, inventory levels and revenue distribution. In the decentralized decision-making model, both parties make decisions independently for their own benefit. By comparing the supply chain operation under the two models, it is found that the centralized decision-making model can maximize the overall profit of the supply chain. To further optimize supply chain coordination, this study introduces the revenue sharing contract model. In this model, the retailer shares part of the revenue to the supplier in order to incentivize the supplier to reduce the wholesale price, thus realizing the overall profit of the supply chain. At the same time, it is also agreed in the contract that the retailer's excess revenue is shared to the supplier at a certain percentage to balance the interests of both parties. Through comparative analysis, under the revenue sharing contract, the price of goods is more competitive, consumer demand is stimulated, and the profit of the whole supply chain is improved. It is further found that under the centralized decision-making model, there exists an optimal export tax rebate rate and import tariff rate that maximizes the supply chain profit. In addition, commodity pricing is negatively correlated with the export tax rebate rate and positively correlated with the import tariff; inventory is positively correlated with the export tax rebate rate and negatively correlated with the import tariff. This provides a theoretical basis for the government to formulate relevant policies. Finally, the theoretical conclusions of this study are verified through numerical examples. The results show that the revenue-sharing contract can effectively coordinate cross-border supply chains and improve overall profits. The government should fully consider the impact of export tax rebates and import tariffs when formulating relevant policies to promote the healthy development of cross-border supply chains.