Abstract: Derris trifoliata, a native liana, commonly associated with mangrove ecosystems, predominantly grows in coastal mudflat shrubs. However, its rapid spread in mangrove ecosystems in recent years has posed a significant ecological threat. This research seeks to investigate the spread patterns of D. trfoliata within mangrove ecosystems and the mechanisms underlying its contribution to mangrove degradation, using Chian’s high-resolution remote sensing data collected between 2013 and 2022. The dataset comprised imagery from GF-1 (2 m resolution), GF-2 (1 m resolution), GF-6 (2 m resolution), and ZY-3 (2 m resolution) satellites, focusing on a representative zone of D. trfoliata expansion at the Nanliu River Coastal estuary in Lianzhou Bay, Guangxi Province. The spatial distribution of mangrove wetlands and D. trfoliata was identified through visual interpretation, while trend analysis was employed to assess changes in vegetation NDVI. NDVI analysis was performed to evaluate the effects of D. trfoliata on mangrove degradation. By 2022, D. trfoliata coverage in the mangrove wetlands of Lianzhou Bay reached 134.4 hm², reflecting a cumulative increase of 92.5 hm² since 2013, at an average annual growth rate of 13.8%. Based on D. trfoliata coverage and the degree of mangrove degradation, three representative expansion areas were classified into slight, moderate, and severe impact zones. D. trfoliata spread ratios were 40.5%, 90.0%, and 89.3%, with corresponding mangrove degradation rates of 12.9%, 43.3%, and 59.5%, respectively.The spread of D. trfoliata primarily follows two patterns: (1) from absence to presence, where D. trfoliata initially appears in spot-like distributions and gradually expands concentrically into mangroves, and (2) from localized patches to widespread coverage, characterized by the coalescence of adjacent D. trfoliata patches and their continuous outward expansion along the boundary. NDVI analysis indicated that NDVI values initially rose before declining during the mangrove degradation process, which spanned approximately 4 to 6 years from the onset of D. trfoliata attachment to complete mangrove loss. These findings offer essential scientific insights for mangrove conservation and the effective management of D. trfoliata.