This paper explores the application of digital technology in civil air defense engineering construction, using the Mudanyuan East Square civil air defense project in Heze, Shandong, as a case study. It analyzes the key challenges faced during the construction process and highlights the value of BIM technology, including reducing temporary construction costs, enhancing pipeline design, improving delivery accuracy, and optimizing construction workflows. To overcome the limitations of the two-dimensional management data gap, a digital platform port integrating quality, safety, labor, and progress management is introduced. The study demonstrates the specific application of BIM technology in civil air defense engineering construction, providing practical reference for process control in similar projects.