Abstract: The emergence of sharing products increases new consumption and supply channels, which not only changes individuals' consumption patterns, but also affects the supply-consumption relationship of traditional products, thereby forming a new multilateral market equilibrium. Due to the characteristics of two-sided market and network externalities of sharing platform, the new multilateral market equilibrium depends on the subjective initiative of participants in C2C sharing pattern, the externalities of two-sided market of sharing platform and their interaction. This study identifies the differences of participants through the differences in perceived value. On the basis of the two-sided market externality interaction, a three-dimensional Hotelling model is constructed to explore the equilibrium mechanism of two-sided market of sharing platform and the tripartite market of product consumption under the intervention of sharing products from two dimensions: the equilibrium of two-sided market of sharing products and the equilibrium of tripartite market under the intervention of sharing products (sharing consumption, traditional consumption, non-consumption). Then, this study recognizes the optimal pricing strategy of sharing platform and traditional economic platform, providing the participants in sharing economy with the foundation of formulating relevant strategies. The findings of this study are as follows. In the C2C sharing pattern, the development scale of potential demand is closely related to the pricing decisions in sharing economy and positively affected by the amount of products on platform (sharing platform and traditional platform), and perceived value differences and externalities in two-sided market play a moderating role in product consumption decision-making; The optimal pricing decision of sharing platform is closely related to the externalities of the supply market, the perceived value differences of suppliers and the supply cost, but has little to do with the consumer market; The maximum profit of sharing platform is positively influenced by the pricing decision and product utility of the similar products, and the externalities and perceived value differences of supply market, but negatively affected by consumer market externalities and the amount of products on traditional platform; When the commission rate of sharing platform is lower than a threshold, traditional platform has the largest profit which is closely related to the supply price and commission rate of sharing products.

Key words: sharing economy, pricing, two-sided market, externality, participant difference