Abstract: Exchange rate regime is of great importance to a country’s economic development and financial stability， and the level of financial development is related to it. Firstly， this article analyzes the economic performance of pegged and floating exchange rate regime respectively. In financial restrict stage， the former demonstrates positive economic effect， but in financial liberalization stage， the latter brings about advantage. Following this， it puts forward financial development level as key explanatory variable， and constructs an econometric model. The res ult demonstrates that financial development level and exchange rate regime elasticity are in positive correlation. At present， our financial infrastructure is not robust， and RMB should be more flexible. When financial liberalization is realized， it can be switched to floating exchange regime.