In the modern medical insurance payment system，DRG payment method constrains medical service behavior and controls the rise of medical expenses through cost risk transfer. However，with the development of economy and medical technology，DRG payment mode has both positive and negative effects on medical service behavior，including information asymmetry，high supervision and transaction costs. In the future，it is necessary to establish a good incentive compatibility mechanism and urge doctors to take the initiative to participate in the reform of payment mode，so as to realize their healthy and sustainable development，effectively optimize the DRG payment mode and exert its positive incentive effect on medical service behavior.