The article constructs the indicators of financial opening, exchange rate fluctuations and financial stability, and then uses the TVP-SV-VAR model to analyze the dynamic relationship of financial openness, exchange rate fluctuations and financial stability based on the impulse response function at different lag stages and different observation time points. The study found that financial openness, exchange rate fluctuations and financial stability have mutually reinforcing effects in the long term. The relationship between the three has a strong time-varying characteristic, and the impulse response functions are relatively important around 2010 and 2017. Impacts of the 2008 financial crisis was relatively short-lived, and impacts of the opening and exchange rate policy period had a sustained positive impact on financial openness, exchange rate fluctuations, and financial stability.