Consumers may be skeptical of the loss of shared products during transactions, generating risk aversion and quality mistrust. To cope with this situation, the blockchain technology needs to be adopted in the sharing platform to track and collect the usage information of the shared products, so as to realize the transparency and traceability of real-time loss information of shared products. In this paper, a dynamic game model of a competitive sharing platform connecting supply and demand sides is constructed by combining bilateral market theory. In this system, consumers are risk-averse, and the two sharing platforms charge platform service fees from both supply and demand sides through supply and demand matching, information transfer and other services. Supply and demand sides choose an ideal sharing platform to complete product service transactions based on risk-averse attitudes and other horizontal differentiation factors. In the actual transaction process, users on the supply side pay costs for providing services on the platform , including costs for product services and product maintenance, etc. Demand-side users have perceived uncertainty about the quality of shared products because they do not know the usage history and life cycle of shared products. Without the introduction of blockchain technology in the platform, the users on the demand side have no access to information about the quality of the shared products due to the lack of disclosure of information about the use of the shared products, so all decisions are made based on expectations. However, the implementation of blockchain in the platform makes the information transparent and traceable by tracking and recording the information on the loss of shared products. As a result, the utility obtained by all users can be updated based on unbiased estimates of randomly obtained quality information. The dynamic pricing and optimal profit of the platform under different scenarios whether blockchain technology is adopted or not are analyzed and compared. The specific timing of introducing blockchain technology to the platform is also discussed using numerical simulations.Results show that:(1) While risk averse consumers get positive information about product quality through the platform blockchain, the pricing of transaction fees for their services by the sharing platform increases with the accuracy of the disclosed product quality information.(2) While the accuracy of product quality information disclosed by the platform blockchain is low, the sharing platform with higher information quality weight can still improve its pricing to consumers based on users' trust in the platform. (3) There are opportunities to create a win-win situation for sharing platforms to disclose product quality information when blockchain technology is introduced at a lower cost and consumers have a higher perceived accuracy of product quality.