Against the backdrop of China’s ongoing county high school revitalization drive, digital upgrading is no longer a secondary technical task—it has become a core tool for narrowing the persistent urban-rural education gaps that have accumulated through decades of education system reform. This analysis draws on 12 months of on-the-ground fieldwork conducted between March 2024 and March 2025 across 16 county regular high schools spanning 8 prefecture-level cities in Shaanxi Province. Sites were selected to cover both the economically developed Guanzhong Plain and the lower-resource Qinba Mountain and Loess Plateau regions, to capture how implementation varies across different local economic and geographic contexts. Data collection included 42 semi-structured interviews with school principals, frontline teachers across nine core subjects, and county education bureau staff responsible for digital education rollout, alongside six student focus groups with 120 11th- and 12th-grade students. This interview data is paired with structured observation notes from 78 in-person class visits across 12 subjects, covering both college entrance exam review sessions and regular new content lessons. The paper explores how digital tools support quality improvement in under-resourced rural campuses, identifies persistent structural frictions that limit program impact even after billions in national infrastructure investment, and proposes context-specific implementation approaches tailored to the unique constraints of county high school settings. Field data show that while basic infrastructure access has reached near-universal levels following national investment campaigns, gaps in teachers’ ability to apply tools in class, locally adapted learning content, and long-term operational support prevent technology from delivering expected benefits. Notably, 75% of sampled schools reported that smart classroom equipment was used in less than 20% of regular, non-inspection class periods. The study finds that meaningful digital support for county high schools requires moving beyond one-time equipment purchases to build integrated, locally rooted systems that prioritize teacher and student needs, rather than forcing schools to adopt uniform models designed for urban key school contexts. These findings carry practical implications for national and provincial education authorities designing digital education policy for rural areas, as well as for school leaders rolling out digital tools on their campuses.