Outdoor site design, as an important part of the early stages of a project, is becoming increasingly important. This study integrates digital technology with traditional site design through the sorting and research of various stages of traditional site design, achieving the digitalization of the entire process of construction project site design, and is supplemented by multiple actual project cases for verification, ultimately forming a digital technology system for site design. At the same time, preliminary exploration was conducted on the automation design based on digital technology, and the automation design of the outdoor site sewage pipeline network in the scheme stage was basically achieved, meeting the preliminary design requirements. The results can provide guidance for the use of digital technology in site design, and propose recommendations for promotion and application.