Abstract: The spatial conflict between cultivated land and orchard land, referred to as the "cultivation–fruit conflict", represents a systematic challenge to food security, ecological sustainability, and rural development in hilly and mountainous regions. Driven by comparative economic incentives, this conflict is characterized by the encroachment of orchards onto high-quality farmland in plains—a phenomenon described as "orchard moving downhill"—and the simultaneous reclamation of ecologically vulnerable steep slopes (>25°) for compensatory cultivation, termed "cultivated land moving uphill". These processes result in substantial environmental degradation, including fertile soil loss, water erosion, and ecosystem deterioration. This study examines Ganzhou City, a typical hilly and mountainous area in southern Jiangxi Province, China. Utilizing multi-temporal land use data (2009–2023), digital elevation model (DEM) data, and cultivated land quality classification data, we developed an integrated "Terrain Niche Index (TPI)–Cultivated Land Suitability" coupling model. This model combines spatial analysis techniques—including kernel density estimation, spatial autocorrelation (Global Moran’s I and Getis–Ord Gi*), and an entropy-weighted TOPSIS method for land quality assessment—to investigate the mechanisms of the cultivation–fruit conflict from the dual perspectives of terrain gradient and cultivated land quality. The results demonstrate that: (1) Between 2009 and 2023, the total area of cultivated land converted to orchard use in Ganzhou reached 20,513.81 hectares, accounting for 4.06% of the total cultivated land, indicating a significant and persistent transformation of agricultural land. Spatially, this conversion exhibited a distinct pattern of being "denser in the east and sparser in the west, with higher rates in the south and lower in the north". Ruijin City and Xunwu County were identified as critical conflict hotspots, strongly associated with the intensive cultivation of high-value crops such as navel oranges and tea oil camellia. (2) The conversion process exhibited a strong terrain gradient constraint, predominantly occurring in flat and gently sloping areas—specifically, valley plains (9,614.69 ha, 46.87%) and low-mountain gentle slopes (9,085.67 ha, 44.29%). (3) Quality analysis revealed that converted land was predominantly high-quality farmland, with Grades 1-3 land constituting 16,554.64 ha (80.7% of total conversion), indicating that the conversion process selectively targets and accelerates the loss of prime agricultural land. (4) Conflict analysis based on a matrix integrating terrain gradient zones and cultivated land quality grades showed that strong-conflict zones covered 15,217.75 ha (74.18% of total converted area), concentrated primarily in valley plains with superior farming conditions. Medium-conflict zones accounted for 3,718.88 ha (18.13%), located mainly on gentle slopes with medium-quality land, emphasizing that the cultivation–fruit conflict occurs predominantly in areas with gentler topography and higher-quality soil. The study proposes a differentiated regulatory strategy based on dual terrain-quality thresholds, offering a scientific framework for balancing cultivated land protection with the development of characteristic forest and fruit industries in southern China's hilly and mountainous regions. The study proposes a differentiated regulation strategy under the dual threshold constraint of ' terrain-quality ', which provides a scientific paradigm for coordinating the protection of cultivated land and the development of characteristic forest and fruit industry in the hilly and mountainous areas of southern China.