At present, the acceleration of urbanization and the increase of ecological concern have led to the rising demand for landscape design. The manual drawing and adjustment process of traditional garden landscape design scheme takes a long time, and the lack of real-time cost monitoring is easy to lead to budget overspending and difficult to comprehensively assess construction safety risks. In order to further realize the overall budget and time management in the design stage, this paper proposes a landscape design method based on 5D intelligent technology. This paper focuses on the application of project planning and simulation, cost estimation and optimization, construction process monitoring, maintenance and management, and focuses on how 5D technology can integrate real-time cost data to help design teams accurately estimate the cost of a project, and adjust and optimize potential budget problems for early detection of projects. The results of the last two groups of simulation experiments are as follows: After the improvement, the estimated cost of landscape is reduced by 61,000 yuan on average, and the comprehensive safety performance is improved by about 37% on average. The study introduced 5D intelligent technology into the field of landscape design, injected innovative elements into the traditional design methods, and provided some practical references for the future development of the industry.