Abstract: To promote the development of health and medical big data and actively promote the safe sharing of medical data,this paper constructs a tripartite evolutionary game model of the system manager,data provider and data demander based on the blockchain architecture.Firstly,prospect theory is combined with evolutionary game,and the parameters of traditional evolutio-nary game are improved by the prospect value function.Secondly,the possibility of game equilibrium and its evolution trend are discussed.Finally,the influence of different factors on the decision-making of each participant in medical data sharing under blockchain architecture is discussed through numerical simulation.The results show that the choice of initial strategy has a signi-ficant influence on the stability of game strategy.The evolution of the system can be accelerated by improving the regulatory bene-fits of the system manager,reducing the perceived losses of the data provider,and improving the compensation of the data demander for actively reporting non-compliance behaviors,thus enhancing the trust of all participants and promoting the formation of trust relationships.

Key words: Blockchain, Medical data sharing, Prospect theory, Evolutionary game