Abstract: Appropriately scaled agribusiness operations are an important pathway for advancing agricultural and rural modernization in China and for building China into a strong agricultural country. Based on 1,130 national-level policy documents related to scaled agribusiness operations in China issued from 1984 to 2024, this study applies natural language processing techniques for text-based quantitative analysis. By integrating the “goal–instrument” perspective with historical institutionalism, it constructs a composite analytical framework to examine the stage-specific characteristics, driving logic, and system composition of policy evolution in China’s scaled agribusiness operations, and further proposes optimization strategies for the future. The results show that: 1) The policy evolution has gone through three stages: initial exploration, nationwide implementation and optimization and refinement. Policy goals have shifted from localized pilot practices under the premise of stabilizing land contractual relations, to active nationwide promotion and system construction, and further to policy optimization centered on linking smallholders with agricultural modernization and addressing the fragmentation of contracted farmland. 2) The policy evolution is the result of the combined effects of institutional contexts, ideas, and actors. It follows a logic characterized by institutional lock-in under the path dependence of the household contract responsibility system, critical breakthroughs under the impacts of globalization and urbanization, and gradual adaptation under the practical constraints of a “large country with smallholder farming”. 3) The current policy system mainly includes three core modules, namely farmland transfer, service-based linkage, and land consolidation, as well as four supporting modules, namely industrialized operation, talent cultivation, fiscal and financial support, and technological innovation. In the future, policy optimization should coordinate engineering improvement with land rights integration to deepen fragmentation governance, improve socialized services and agricultural machinery support to release the scale benefits of contiguous operation, and configure policy instruments according to regional resource endowments and farmland engineering conditions. From a long-term policy text perspective, this study reveals the evolutionary pattern of China’s policies on appropriately scaled agribusiness operations and provides a reference for improving the policy system and promoting agricultural modernization under the background of a “large country with smallholder farming”.