In the context of rapid urbanization, outdoor landscape and pipe network design has become an indispensable part of architectural planning and landscape design. Faced with the design challenges posed by complex terrain, traditional methods have been criticized for their time-consuming and high error rate. In this study, Dynamo visual programming technology was introduced to explore its application in outdoor pipe network design, especially in the creation of BIM models and collision detection of 3D sites, green plants and outdoor pipe networks, in order to improve design efficiency and reduce construction risks. Through practical project applications, this paper first demonstrates the application of Dynamo in modeling and clash detection. The design team used Dynamo to convert 2D drawings into 3D BIM models, improving the visualization of the design. Then, this technology was utilized to quickly establish outdoor site models, green plant models, and pipe network models. Effective clash detection between tree pits and underground pipelines was carried out, the planting positions of green plants were optimized, and construction conflicts and damages were avoided. Finally, suggestions for the promotion and application of the research results are put forward to provide reference and guidance for similar projects.