The financial sector provides a channel for the optimal allocation of resources for the real economy and it is an important support for the high-quality development of the economy as well. Based on the data from 2013 to 2019 of 11 provinces along the Yangtze River Economic Belt，this paper empirically analyzes the influence of the financialization of manufacturing industry on the quality of economic development，and draws the following four conclusions. （1）In terms of short-term effects，the financialization of manufacturing industry can significantly improve the quality of economic development by giving play to the “reservoir” effect，but in the long run，the “crowding out” effect is the main effect，which is not conducive to improving the quality of economic development. （2）The level of regional financialization promotes the short-term “reservoir” effect of the financialization of manufacturing industry；Financing constraints have an inhibitory effect on the “reservoir” effect，which is not conducive to improving the quality of economic development. Regional financial regulation has no significant effect on the quality of economic development due to the financialization of manufacturing industry. （3）Generally profitable enterprises and medium-sized enterprises improve their financialization level，which has a more significant impact on the quality of economic development. （4）The mechanism test shows that reducing the degree of information uncertainty and increasing the investment in main business are the two important ways for the financialization of manufacturing industry and improve the quality of economic development in the short term.