Based on the context of implementing an innovation-driven development strategy and promoting the construction of a digital infrastructure system in China, the theoretical mechanism of digital infrastructure driving technological innovation is systematically analyzed from the perspective of innovation input-output. Utilizing text information mining and provincial panel data from 2011 to 2021, a panel vector autoregression (PVAR) model was applied to examine the empirical relationship between digital infrastructure and technological innovation. Furthermore, a dynamic stochastic general equilibrium (DSGE) model, incorporating a technological innovation sector, was constructed to reveal the transmission pathways and effects of digital infrastructure on technological innovation through numerical simulation. The empirical results indicate that both digital infrastructure investment and the current level of digital infrastructure have a long-term positive impact on technological innovation. Simulation results further demonstrate that digital infrastructure investment positively influences independent innovation and short-term imitative innovation through R&D labor and resource allocation. The current level of digital infrastructure positively affects medium- and long-term independent innovation as well as short-term imitative innovation through R&D funding, innovation subsidies, and the quality of the digital technology environment. The impact effects of the two types of shocks exhibit characteristics of "gradual accumulation with delayed impact" and "immediate effect, " respectively. The findings provide theoretical support and policy reference for the government to guide and fully unleash the technological innovation effects and economic benefits of digital infrastructure.