Abstract: The outbreak of COVID-19 has led to a surge in the demand for medical protective equipment such as masks. Some enterprises have engaged in disorderly behaviors such as price gouging and manufacturing and selling fake goods, which have made the prevention and control of the epidemic more difficult. At this time, the government is needed to supervise the market. It is necessary to design a practical solution that can stabilize the market order in the shortest time. In order to discuss the dynamic mechanism of medical protective equipment market supervision, a three-agent static evolutionary game among local government, protective equipment company, and consumer is established. Through the sensitivity analysis, it is found that the sensitivity index of each key parameter is less than 1, and the model has good robustness. Based on static evolutionary game model, a dynamic penalty model and a dynamic penalty-subsidy model are constructed in order. System dynamics is used to simulate the stability of each evolutionary equilibrium solution under different mechanisms, and Lyapunov's stability theorem is used to verify the equilibrium point of evolutionary stability. The results show that: (1) under a completely static mechanism, the game process of the three game players cannot reach a stable equilibrium state. (2)The introduction of dynamic punishment, subsidies and other methods can better suppress the behavioral fluctuations of the game subject, and urge protective equipment companies to take honest management as their better choice. (3) A new type of non-linear dynamic penalty-subsidy mechanism is proposed, under which the incentive effect is the best. And the protective equipment enterprise reaches the ideal stable situation on the fifth day. Some ideas for local governments are provided to design a reasonable and standardized medical protective equipment market plan under the COVID-19 epidemic situation.

Key words: COVID-19; medical protective equipment; evolutionary game; system dynamics; dynamic mechanism