Abstract: With the increasing demand for forest quality improvement and sustainable management, traditional forest tending and thinning practices have difficulty in balancing stand structure optimization and ecological function enhancement. Based on close-to-nature forest management theory, this study aims to develop a forest tending and thinning technical system suitable for southern China and to evaluate its effectiveness. By systematically analyzing the limitations of conventional thinning methods, close-to-nature thinning measures focusing on target tree cultivation, stand structure optimization, promotion of natural regeneration, and protection of ecological elements were proposed. Artificial pure stands of Pinus kesiya var. langbianensis and natural conifer–broadleaf mixed forests in Sanmu State-owned Forest Farm were selected as case studies. From 2020 to 2023, changes in stand structure, target tree growth, and ecological indicators before and after thinning were monitored and compared. After close-to-nature thinning, the average annual diameter at breast height (DBH) increment of target trees in artificial Pinus kesiya stands increased by 75%, and understory vegetation coverage increased from 12% to 65%. In natural conifer–broadleaf mixed forests, the average annual DBH increment of target trees increased by 80%, the natural regeneration rate of broadleaf species reached 60%, and the ecosystem service function index increased by approxi- mately 20%. Close-to-nature thinning techniques can effectively enhance both the management quality and ecological benefits of forest stands, providing a reliable technical approach for the sustainable management of plantations and secondary forests, and supporting the transformation of forestry toward ecology-priority and quality-oriented development.