Abstract: The expansion of farmland transfer has profoundly reshaped China’s agricultural landscape, giving rise to a growing group of external large-scale farmers who lease land across administrative and social boundaries. Ensuring that these external operators adopt green production technologies is crucial for achieving a sustainable agricultural transformation. However, despite their increasing prominence, the mechanisms through which land tenure arrangements and social contexts influence the green technology adoption behaviors of these farmers remain insufficiently understood. This study aims to fill this gap by examining how the stability of farmland transfer rights affects the green technology adoption behaviors of external large-scale farmers, with a particular focus on the mediating roles of risk perception and village embeddedness. Grounded in property rights and embeddedness theories, this study conceptualized tenure stability as a multidimensional construct encompassing the legal, factual, and perceived security of operational rights. The analysis drawn on micro-level survey data from 378 external large-scale farmers in Fujian Province and employed ordinary least squares regression and mediation models to test the proposed hypotheses. To ensure robustness, the study further applied 5% percentile Winsorization, variable substitution, and instrumental variable (IV) techniques. The empirical results demonstrated three major findings. 1) Tenure stability substantially promoted green technology adoption across all three of its dimensions. Legal security (e.g., formal contracts and enforceable rights) provided the institutional guarantees for long-term investment; factual stability (e.g., stable use and minimal disputes) ensured operational continuity; and perceived stability (e.g., subjective confidence in land retention) shaped behavioral expectations. Together, these dimensions strengthened the willingness of external farmers to commit to sustainable production practices. 2) Risk perception mediated the relationship between tenure stability and technology adoption. When farmers perceived their operational rights as secure, their psychological barriers to adopting green production technologies were lowered, as these technologies were viewed as less risky or uncertain. 3) Village embeddedness exerted a substantial moderating effect. Stronger embeddedness — reflected in trust-based relationships, reputation networks, and reciprocal cooperation within rural communities — attenuated the negative influence of perceived risk and reinforces the positive impact of tenure stability on adoption. In contrast, weakly embedded farmers faced higher social transaction costs, limited access to information, and lower credibility in cooperative arrangements. These findings advanced the literature in several ways. First, the study established an integrated analytical framework that links institutional security, risk cognition, and social embeddedness, thereby bridging the divide between formal property rights and informal rural governance. Second, it provided rare micro-level empirical evidence of the behavioral mechanisms governing external large-scale farmers, a group often marginalized in land and sustainability research. Third, it highlighted the dual governance logic of “institutional incentives and relational embeddedness”, offering new insights into how formal and informal systems jointly shaped ecological behaviors in transitional rural economies. The policy implications are twofold. Institutionally, enhancing the stability and enforceability of farmland transfer contracts can strengthen investment incentives and reduce perceived risks for external operators. Socially, governments and local organizations should encourage inclusive community integration by fostering shared values, mutual trust, and benefit-sharing mechanisms between migrant farmers and local residents. Together, these efforts can promote a virtuous cycle of secure tenure, reduced risk, and sustainable agricultural innovation.