Abstract: Drug quality is related to public life and health, national economic development, social stability and national security, and has always been one of the hot issues concerned by the government and the whole society. Accelerating circulation of medicines in the context of "Internet + medical health" has expanded the scope of drug safety issues, therefore, establishing a patient feedback mechanism is an effective way to promote Internet drug quality supervision. Considering how to design an Internet drug quality supervision strategy under the patient feedback mechanism, based on the evolutionary game theory, a four-party evolutionary game model of drug quality supervision is constructed by drug manufacturers, medical e-commerce companies, government regulatory authorities and patients. The government regulation strategy and patient feedback mechanism to promote the supply of high-quality drugs by drug manufacturers are explored by analyzing the stability of the each player's strategy selection and the stability of 16 equilibrium points of replication dynamic system based on Lyapunov first rule. And the impact of each element on the evolution of various strategies is performed simulation analysis using Matlab 2017. The results show that: 1) The more likely patients are to have a distorted evaluation or a lower complaint rate, the more likely medical e-commerce companies are to choose not to test the quality of drugs, which is not conducive to the quality and safety of drugs on the Internet; 2) Under the evaluation of patient distortion, there is no stable strategy combination for drug manufacturers to provide high-quality drugs, and the effective feedback mechanism and supervision mechanism under real evaluation can make the quality of Internet drugs stable; 3) Improving the reputation added or reputation loss brought by patients' evaluation for pharmaceutical e-commerce companies and pharmaceutical manufacturers will make drug manufacturers choose to provide high-quality drugs as a stable strategy; 4) Reducing the rate of distorted comment of patients and increasing the behavior of complaining to defend rights both can enhance the stability of drug manufacturers in providing high-quality drugs. Finally, combined with evolutionary game model and simulation analysis results, the countermeasures and suggestions for improving the drug quality supervision mechanism are proposed.

Key words: "Internet + medical health", patient feedback mechanism, drug quality supervision, evolutionary game, simulation analysis