At present, the confrontation in cyberspace is becoming more and more fierce, and network attacks and defenses have become the main form of confrontation between parties in cyberspace. The maximum benefit can be obtained by using scientific decision-making. Traditional network attack and defense research mainly focuses on the relationship between network attackers and network defenders, but enough to explain the benefits of in the evolution of network attacks and defenses. In view of this, this paper constructs a tripartite evolutionary game model among network attackers, network defenders and government regulators, analyzes the evolutionary stability of each participant's strategy choice, discusses the influence of each element on the tripartite strategic choices, and further analyzes the stability of the equilibrium point of the tripartite evolutionary system. The research results show that (1) the timely supervision of the network by the government supervision department is conducive to enhancing the construction of network security and has strategic significance for the security of cyberspace; (2) the network defense department can obtain more effective defense measures when being attacked by the network; (3) the network defense party can analyze the strategic defense requirements that are more in line with its own benefits. Finally, we use Matlab2021a to conduct simulation analysis, verify the effectiveness of the evolutionary game model under different initial conditions, and put forward reasonable suggestions for network defenders and government regulators according to the analysis conclusions.