Currently, the global economy is in a critical period of digital transformation, and governments have been pushing forward the reform of the fiscal and taxation system to adapt to the new development pattern. Based on the panel data of 30 provinces in China from 2014 to 2024, this paper empirically investigates the impact mechanism of digital fiscal and tax innovations on optimizing the regional tax system and promoting the high-quality development of the economy by applying the Linked Panel Equation Model (LPEM), the mediation effect test, and spatial econometric methods. The study found that: digital fiscal innovation is significantly and positively related to economic high-quality development, with a correlation coefficient of 0.205; the regression coefficient of governmental fiscal expenditure preference on economic high-quality development reaches 10.633, and the regression coefficient of tax effort is 0.114, both of which are significant at the 1 percent level; The Sobel test and Bootstrap method confirm that the regional tax system plays a mediating role in the process of digitalized fiscal innovation affecting the high-quality development of the economy; the spatial autocorrelation test shows that the Moran’s I index of high-quality development of the economy in 2024 is 0.066, which indicates that there is a significant spatial positive correlation. This study provides empirical support for deepening the reform of fiscal and taxation system and promoting regional coordinated development.
