Financial technology has accelerated the process of financial disintermediation in banks, and studying the impact mechanism of financial technology on banking business is crucial for the transformation of commercial banks. The VAR model was used to analyze the quarterly data of commercial banks' net income from loans, deposits, fees and commissions from 2017 to 2022, and the scale of third-party Internet payment transactions in the corresponding market. The VAR model was established to analyze the impact of financial technology on commercial banks' assets, liabilities, and intermediary business and the corresponding interpretation contribution. The study found that the scale of third-party Internet payment transactions has an obvious reverse effect on the asset business of commercial banks in the first five periods. In addition, the combination of Yu'e Bao's money market fund and third-party Internet payment transactions has a positive and negative effect on commercial banks' liabilities and intermediary business in turn.