With the rise of omnichannel retailing of online and offline integration, the shopping option of buy online and pickup in store(BOPS) has gained increasing attention. This paper focuses on the coordination of an omnichannel supply chain consisted of one online manufacturer and one offline retailer with sales efforts under the BOPS model. Based on the game theory and optimization theory, we derive the integration models of BOPS sales counted in online channels and BOPS sales counted in offline channels, and study the coordination problem of the omnichannel supply chain based on sales effort cost allocation mechanism. The conclusions show that centralized decision-making can improve the level of sales efforts and the overall performance of the supply chain, and BOPS sales counted in online channels can make the supply chain system more profitable. Under the premise of meeting the participation constraints, the cost-sharing contract in different BOPS channel integration models can alleviate the double marginalization effect, stimulate the improvement of sales effort effectively, and achieve Pareto improvement of the supply chain system's revenue and effectively coordinate the omnichannel supply chain.