Abstract: The brutal growth of P2P online loan platforms has led to intensive exposure of risks in China's online loan industry. Taking the P2P online loan platform as a pure information intermediary service as a starting point, this paper constructs an evolutionary game model between the P2P online loan platform and financial regulatory agencies, study the strategic choices of the two players in the game process, and use Matlab software to simulate different situations the equilibrium point of the evolutionary stability strategy. The study finds that when the incentives provided by online loan platforms for providing pure information intermediary services are less than the other net benefits obtained by providing non-pure information intermediary services, and the regulatory benefits under the strong supervision of financial regulatory authorities are greater than the regulatory costs, P2P online lending platforms can provide pure information intermediary services, and the equilibrium point between the evolution of the two reaches an "ideal" state. The study also finds that increasing the "rent-seeking" costs of online loan platforms, increasing the penalties for providing non-pure information intermediary services on online loan platforms, and increasing the regulatory revenues of financial regulatory authorities can effectively make the system away from the "worst", "invalid" and "bad" states and graudally toward the "ideal" state, realizing a double Pareto improvement of P2P online loan platforms and financial regulatory authorities.

Key words: P2P online loan platform, pure information intermediary, evolutionary game, Matlab simulation