Abstract: This study moves beyond prior research that evaluates farmland-scale management and service-scale management independently by examining their combined effects on grain-production resilience from a coordinated-development perspective. Using the entropy-weight method, we measure provincial-level grain-production resilience from 2008 to 2023 and explore how scale management shapes grain-production resilience from both theoretical and empirical perspectives. The results show that both farmland-scale management and service-scale management significantly enhance grain production resilience and generate clear synergies. These synergies are stronger in non-major grain-producing regions and in regions with larger per capita sown areas. Farmland-scale management enhances resilience by expanding planting scale through horizontal specialization, whereas service-scale management alleviates farmers’ production factor constraints through vertical specialization. Their joint synergistic effect further improves grain production resilience by facilitating rural labor transfer and promoting technological progress. The two modes form a mutually complementary system that jointly enhances grain-production resilience. Future efforts should strengthen the linkage between horizontal and vertical specialization, enhance institutional support in regions with stronger synergies, and continuously improve the supporting system and regulatory framework for scale management.