Abstract: Digital rural construction has become a critical engine for promoting the transformation of agricultural modernization, yet its innovation-driven effects require systematic examination. Based on panel data from 30 Chinese provinces (excluding Hong Kong, Macao, Taiwan, and Xizang) over the period 2011–2022, this study investigates the impact of digital rural construction on agricultural technological innovation from the perspective of the innovation value chain. The results show that: 1) digital rural construction significantly promotes agricultural technological innovation. At the technology R&D stage, the marginal effect increases with the level of digital rural construction, exhibiting a typical network effect; at the achievement transformation stage, once the R&D level crosses the first threshold, its promoting effect increases significantly. 2) Mechanism analysis indicates that capital availability, labor transfer, and land transfer play mediating roles in the process through which digital technologies empower agricultural technological innovation, while the enhanced vitality of traditional production factors further strengthens this effect. 3) Regional heterogeneity analysis reveals that, at the technology R&D stage, digital rural construction has significant positive effects in both eastern and western regions, but shows an insignificant negative effect in the central region; at the achievement transformation stage, its promoting effect displays a decreasing gradient from east to west. These findings provide theoretical foundations and empirical evidence for optimizing the national agricultural innovation network and advancing the deep empowerment of agricultural modernization through digital technologies.