Abstract: Driven by the information revolution, the coupled development paradigm of "integration but independence, mutual promotion but mutual restriction" between finance and technology has gradually become a consensus, and finance technicalization and technology financialization have become the normality and characteristic of economic development. Although the coupling of finance and technology is deepening the integration of finance industry and technology industry, it also increases the concealment and complexity of systemic risk. Research on the vulnerability of the coupling of finance and technology is a "genetic" exploration of systemic risk, which is of great value and significance. Based on the background of high-quality economic development, the process of economic transformation to high-quality development is divided into the turning period, the entering period and the development period, and the coupled network model of finance and technology is constructed by using complex network theory, which deeply reveals the basic topological properties and structural characteristics of the coupled network, and the vulnerability of the coupled system is also investigated in the three periods. Empirical research shows that: first of all, the industry coupling degree between finance industry and technology industry is on the rise with the economic transformation to high-quality development. High-quality technology innovation has become the key to promote the development of technology industry and the benign coupling of finance and technology. Secondly, small and medium-sized enterprises play an important role in improving the efficiency of coupled network. The tight coupling between small and medium-sized enterprises is an important structural feature of the coupled system. Thirdly, the vulnerability of the coupling of finance and technology is declining, and the influence of extremely important enterprises on the risk of the coupling system is gradually weakening. In addition, it is also found that the size of an enterprise is still the key to determine its vulnerability impact force (the impact force formed when vulnerability is stimulated). Industrial and Commercial Bank of China, China Construction Bank and other large state-owned commercial banks have the strongest vulnerability impact force, but their risk spillover is weak. The enlightenments and policy suggestions are as follows: firstly, the convergence and driving role of medium-sized enterprises should be stimulated, and the stepped mutual promotion mode can be tried to solve the investment and financing problems of small and medium-sized enterprises. Secondly, the regulatory strategy of "too big to fail" is more suitable for the risk management of China's coupling system of finance and technology than the management concept of "too connected to fail". Despite their outstanding performance in improving network efficiency, the vulnerability impact of small and medium-sized enterprises is still much weaker than large enterprises. It indicates that "too related" enterprises will not have a big risk impact on the system, but "too big" enterprises still have the potential to have the greatest risk impact ability in the current coupling system of finance and technology in China. Thirdly, enhancing the ability of high-quality innovation and continuous innovation, activating and improving the efficiency of the coupling system with high-quality innovation supply, and promoting the coordinated and stable development of the subsystem with continuous innovation are the keys to reduce the coupling vulnerability of finance and technology.