Abstract: In current urban construction, local governments have been actively involved in transforming the external morphology of Prefabricated public toilet buildings to enhance their aesthetic appeal and improve urban landscapes. Prefabricated public toilet buildings, recognized for their efficiency and environmental benefits, are widely adopted. However, challenges persist in the installation and positioning of aluminum single-panel roof formations, which demand high precision, while construction efficiency, positioning accuracy, and installation precision remain difficult to control. Additionally, roof waterproofing issues draw significant attention. Therefore, this study focuses on researching key technologies and processes for complex roof formwork construction and roof waterproofing in prefabricated public toilet buildings, aiming to improve construction quality and advance the high-quality development of public toilet infrastructure. Employing case study analysis and field research, this paper investigates representative prefabricated public restroom projects. Through detailed observation and documentation of construction processes, key aspects of complex roof formwork and waterproofing were analyzed. Combined with construction drawings and regulatory requirements, the study optimizes construction workflows and proposes targeted technical measures. The findings reveal that optimizing aluminum panel processing techniques and installation procedures effectively enhances roof formwork installation accuracy and construction efficiency. For roof waterproofing, the composite application of multi-layer waterproof materials and reinforced waterproofing at critical joints significantly improve waterproofing performance. Furthermore, optimized workflows ensure tighter coordination between construction phases, reducing time and costs.