Abstract: To improve the landscape quality of urban gateway transportation corridors, a bougainvillea landscape enhancement project was carried out targeting the problems of aging plants, soil compaction, and poor landscape effect in the median strip of Hong Kong Airport Expressway. Based on the technical accumulation of bridge greening in Lingnan region and the subtropical monsoon climate characteristics of Hong Kong, a full-process construction technology system was systematically constructed, including variety selection, plant cultivation, seedling transportation, construction enclosure, and facility installation. A refined maintenance plan was established, covering shaping and pruning, green prevention and control of diseases and pests, response to extreme weather, and precise flowering period regulation. Combined with project practice, optimization strategies were proposed from five dimensions: planning optimization, standard formulation, variety innovation, technology upgrading, and intelligent empowerment. This study provides a replicable and promotable technical paradigm for bridge greening projects in the Guangdong-Hong Kong-Macao Greater Bay Area and other regions with similar climates, and has important practical significance for promoting the high-quality development of urban vertical greening.