There is a close connection and logical relationship between RMB internationalization and capital account opening. Research shows that the internationalization strategy of RMB and the opening policy of the capital account feature an intersection, and the internationalization degree of RMB and the opening level of the capital account feature a convergence, RMB internationalization will promote the opening of capital accounts through many mechanisms,such as forcing capital account opening, increasing capital account opening benefits, reducing capital account opening risks, replacing and overlapping capital project opening. This paper constructs a TVP-SV-VAR model for empirical testing and shows that the delayed impact of RMB internationalization on capital account opening is greater than the immediate impact, and the degree of impact varies with changes in the macroeconomic situation.Based on the development perspective of“one body, two sides”of RMB internationalization and capital account opening, combined with currency substitution theory,this paper explores and proposes a feasible path and safeguard measures to gradually realize the opening of the RMB capital account in the process of using the RMB as a global trade settlement currency, a global investment financing currency, a global financial foreign exchange transaction currency, and a global reserve currency.It is expected to provide new ideas and perspectives for advancing the internationalization of the RMB and the opening of the capital account.