An evaluation index system for agricultural science and technology (S&T) innovation capacity and agricultural high-quality development was constructed using the entropy method. By integrating these indices with a binary system coupling coordination degree model, the coupling degree and coupling coordination degree for provincial-level administrative regions from 2010 to 2020 were calculated. It is found that the agricultural S&T innovation capacity and the comprehensive index of agricultural high-quality development have shown a significant upward trend since 2010, reflecting the thorough implementation of the innovation-driven development strategy in the agricultural sector. The comprehensive index of agricultural high-quality development displays a distinct regional hierarchy: east > central > west > northeast. The eastern region leads in agricultural S&T innovation capacity, followed by the central and northeastern regions, with the western region showing relatively weaker innovation capacity. While the interaction between agricultural S&T innovation capacity and agricultural high-quality development is strong, the depth of this positive interaction remains limited. The system coupling degree has gradually increased and is nearing 1, indicating more frequent interactions between the two systems. However, the coupling coordination degree is significantly lower than the coupling degree, suggesting that the positive interactions between the systems are insufficient, and the potential synergies between them have not been fully realized. In response, several policy recommendations are proposed, including accelerating new quality agricultural productivity, improving the institutional mechanisms for agricultural S&T innovation, capitalizing on the advantages of the burgeoning digital technology sector, and advancing the development of smart agriculture.