Using provincial sample data from 2015 to 2021, this study investigates the impact of the informatization construction of national audit on people’s livelihood-related expenditures. The research findings are as follows: the informatization construction of national audit can increase the people’s livelihood-related expenditures. The conclusion remains constant after robustness tests and endogenous tests. The mechanism analysis shows that the important mechanisms for increasing the people’s livelihood-related expenditures by the informatization construction of national audit include national audit playing information transmission effect and supervisory accountability effect. The heterogeneity analysis shows that the impact of informatization construction of national audit on the people’s livelihood-related fiscal expenditures varies across different regions, auditor sizes and public demands. The results of this study provide some insights for audit institutions to insist on strengthening audit through science and technology and local governments to optimize the structure of fiscal expenditures.