In order to improve the green construction level of roads in dense urban areas, combined with the project characteristics and engineering requirements of Nanzhong Expressway, the concept of green development was implemented in the whole life cycle of road design, construction, operation, maintenance and management. Focused on the research and development of ten innovative technologies in four categories, including industrial intelligent construction of bridge cluster highway, comprehensive utilization of highway resources, road environmental protection in coastal wet areas, and integrated design of transportation and tourism in the Guangdong-Hong Kong-Marco Greater Bay Area. Among them, the prefabricated beam annular production line and non-standard eight-lane are the first technologies featured in the project. In addition, the technical system of green bridge cluster highway in typical urban agglomerations have been initially constructed, and the key development directions in the future are prospected to enrich and improve the green road technology system of Guangdong-Hong Kong-Marco Greater Bay Area. This provides a reference for the sustainable development of other highly urbanized regions.