Financial S&T expenditure is very important for promoting national S&T innovation and high-quality development. Firstly, the LP method was applied to measure the total factor productivity of enterprises and the economic transformation ability of fiscal S&T expenditures in Xi’an city was discussed. Secondly, taking the Xi’an listed companies in Shanghai and Shenzhen from 2012 to 2022 as samples, an empirical research on how fiscal S&T expenditures affect the TFP of enterprises was conducted through the method of matching with macro data. The results show that increasing the intensity of fiscal S&T expenditures helps to improve enterprise total economic productivity. In view of this, in order to improve the total industrial productivity of enterprises in Xi’an and to play the role of leverage of fiscal S&T inputs on economic development, not only the input-output structure of fiscal S&T expenditures should be considered, but also relevant suggestions should be put forward from the government’s point of view.