Abstract: This study employs provincial panel data from 2013 to 2022 and adopts a two-way fixed effects model alongside a mechanism testing model to analyze the impact of new-quality agricultural productivity on food security and its underlying mechanisms. The findings reveal that: (1) New-quality agricultural productivity significantly enhances food security, a conclusion robust to multiple sensitivity tests; (2) The positive effect operates through the mediating channel of socialized agricultural machinery services; (3) Heterogeneity analysis indicates that new-quality agricultural productivity markedly improves food security in major grain-producing regions and areas with high fiscal support for agriculture, whereas its impact is statistically insignificant in non-grain-producing regions and regions with limited fiscal resources. Confronted with mounting pressures on national food security, policymakers should prioritize context-specific development of new-quality agricultural productivity, amplify its role in driving agricultural modernization, rigorously implement the “storing grain through technology” strategy, adaptively optimize farming systems and crop structures, and holistically strengthen the foundation of food security.