In the context of worsening global climate change, the transition to a low-carbon economy has become an urgent task for the international community. The sharing and circulation of carbon emission data is of great significance to improve the effectiveness of emission reduction measures and promote the development of the global carbon market. In order to promote carbon neutrality, solve the security needs of carbon data sharing, and promote the realization of carbon data circulation and carbon neutrality goals, this paper designs a carbon data sharing architecture that supports carbon data circulation, and proposes a blockchain-based carbon data sharing incentive mechanism. Data information entropy and participation enthusiasm are used to evaluate the performance of carbon data providers from multi-dimensional carbon data value measurements, and the fairness of the Shapley value algorithm is improved to adjust the benefit distribution among multiple contributors. Finally, the simulation experiments designed in this paper show that compared with the fixed-value incentive mechanism, the incentive mechanism in this paper can effectively increase the amount of carbon data in the carbon data sharing platform.