Abstract: In order to study the platform advertising strategy of a merchant under e-commerce platform membership mechanism, this paper establishes game models under two scenarios where the merchant does not introduce platform advertising and introduces platform advertising through e-commerce platform membership mechanism, and identifies the merchant's platform advertising strategy selection mechanism and the impact of platform advertising strategy on the decisions and profits of supply chain members by reverse induction and comparative analysis. Results show that when the member price discount is less than a certain threshold or when the member price discount is greater than a certain threshold and the commission rate is less than a certain threshold, the merchant should not introduce platform advertising; when the member price discount is greater than a certain threshold and the commission rate is greater than a certain threshold, whether from the perspective of profit maximization or market share maximization, introducing platform advertising is a "win-win" strategy for the merchant and the platform. Introducing platform advertising is always detrimental to nonmembers, and beneficial to members when the commission rate and the member price discount meet a certain condition. To ensure the rights and interests of members and the diversity of product categories with price discount exclusive to members, the platform should set member price discounts based on different commission rates for each product category.