Under the sharing economy model, how value is co-created has changed significantly, with users beginning to participate more actively and proactively in the value creation process of enterprises, gradually becoming the core driver of value creation. Virtual knowledge communities have developed rapidly among the application areas of the sharing economy. In the context of high-quality development, the flourishing development of virtual knowledge communities helps promote the entire flow of knowledge in society and better serves the national innovation-driven development strategy. At the same time, a series of problems have emerged in the rapid development of virtual knowledge communities, such as poor user experience, a single way of realization and uneven content in the communities. As an important channel and hub for users to exchange information and acquire knowledge, the core problem that virtual knowledge communities need to solve is attracting users and motivating them to share their expertise and actively participate in the value-creation process. Based on the Zhihu case, this paper aims to explore the value co-creation mechanism of users in virtual knowledge communities to optimize platform services, enhance user participation and promote the exchange and dissemination of knowledge.