Based on the adaptive expectation theory,this paper constructs a theoretical model of RMB exchange rate expectation.On this basis,the generalized moment estimation method is used to evaluate the effect of the expectation of RMB exchange rate on cross-border capital flow,and the VAR model is used to empirically test the dynamic impact of the expectation of RMB exchange rate on cross-border capital flow.Research finds that the expected dynamic adjustment of RMB exchange rate contains some irrationality in the adaptive process,the expected change of exchange rate has the largest impact on settlement of exchange capital,followed by long-term cross-border capital and short-term cross-border capital.When the expectation of RMB exchange rate depreciates,cross-border capital circulation speeds up,but short-term cross-border capital flows back after the outflow reaches a certain level.Cross-border capital flow is mainly determined by its own pre-value,but the expected change of the expectation of RMB exchange rate has a great impact on cross-border capital flow.