Abstract: Against the backdrop of the rapid development of global digital currencies and the coordinated promotion of RMB internationalization, it is of great significance to evaluate the macroeconomic impact of the innovative mechanism of digital RMB. Based on the dynamic stochastic general equilibrium model of the open economies of the two countries and considering the digital RMB as a digital legal tender tool that combines payment convenience and liquidity services, this paper conducts a study. The findings show that the innovative mechanism of digital RMB can promote the linkage between trade and capital flow by reducing payment friction and optimizing asset portfolio. The cross-border operation of the innovative mechanism of digital RMB may still be affected by liquidity constraints, settlement frictions, and fluctuations in overseas acceptance, which will amplify the transmission of external shocks to exchange rates and cross-border capital flows, and weaken the cross-border settlement efficiency of digital RMB. The policy simulation results show that the dual objective Taylor rule under the traditional monetary policy framework has limited effectiveness; in contrast, targeted interest rate spread subsidies can stabilize expected returns and reduce external imbalances and exchange rate overshoots. The above conclusion indicates that a dynamic monitoring and information disclosure system covering clearing arrangements, liquidity support, and risk management should be established, supplemented by targeted macroprudential tools for the digital RMB market, and coordinated with monetary policy and capital account management, in order to effectively control macroeconomic fluctuations while improving cross-border efficiency.

Key words: digital RMB innovation mechanism, cross-border use constraints, macroeconomic fluctuations, dynamic stochastic general equilibrium (DSGE)