In recent years, the information technology is developing rapidly, and is closely combined with government activities, creating new opportunities for improving the efficiency of government budget funds. This paper selects panel data of prefecture-level cities in China from 2016 to 2019, using DEA-Tobit two-step method to analyze the influence of government affairs informatization on the efficiency of local government budget funds and its mechanism. It is found that the higher level of government affairs informatization contributes to the improvement of the efficiency of local government budget funds, and the improvement effect of government affairs informatization on the efficiency of local government budget funds is more obvious in areas with strong national audit function effect or good trust environment. The mechanism analysis shows that government informatization can improve the efficiency of local government budget funds through improving financial transparency and public attention. Finally, this paper puts forward some policy suggestions on how to improve the efficiency of the use of budget funds by local governments in order to provide reference for relevant government departments.