Constructing a natural artificial forest in the core area of the city holds substantial significance for planning urban green space systems. Using the Shuangzi Mountain project at the Shanghai World Expo Cultural Park as a case study, the study thoroughly examines traditional techniques for soil and rock mountain stacking. It offers a comprehensive summary of the technical system for creating mountainous landscape over cavity structures. This study emphasizes addressing critical issues such as load control on these cavity structures, soil stability in mountainous areas, and the facilitation of effective tree growth. A systematic solution has been proposed through technological advancements in various domains, including soil research and development, traffic organization planning, earthwork backfilling technology, soil stabilization measures, tree fixation systems, and drainage system design. Also, this study verifies the feasibility of constructing urban forest landscape but also optimizes essential technical parameters through extensive monitoring and empirical analysis. It provides a scientific foundation and technical support for designing and implementing similar projects, serving as a valuable reference for urban ecological restoration and landscape optimization.