Abstract: To promote the sustainable use of cultivated land and improve the effectiveness of acidified cultivated land governance, this study uses survey data from 1,381 farming households in Hubei, Anhui, and Guangxi collected in 2025 to empirically examine the impact of environmental regulation on farmers’ cultivated land management behavior and its underlying mechanisms in the context of acidified cultivated land management in southern China. The results show that environmental regulation significantly promotes farmers’ acidified cultivated land management behavior, and this effect is mainly realized by enhancing farmers’ environmental awareness, including pro-environmental identity and environmental cognition. In addition, risk-averse attitudes strengthen the positive effect of environmental regulation on farmers’ acidified cultivated land management behavior. Heterogeneity analysis further indicates that the promoting effect is more pronounced among young farmers, farmers with weaker environmental perception ability, farmers operating land with lower degrees of acidification, and farmers with expectations of declining income. Further analysis reveals that environmental regulation not only significantly increases the adoption of key soil improvement technologies, such as organic fertilizer application and soil conditioner application (e.g., lime), but also significantly enhances farmers’ willingness to engage in acidified cultivated land management and their willingness to adopt new technologies. Based on these findings, this study suggests strengthening supervision and enforcement of farmland environmental pollution control, while coordinating with incentive-based policies such as subsidies and technical training; promoting integrated management technology systems centered on organic fertilizers and soil conditioners; improving publicity and training on acidified soil knowledge and management technologies to enhance policy information dissemination efficiency; and implementing differentiated governance and support policies to improve the precision and sustainability of acidified cultivated land management.