In the construction of the street crossing SB-01 in busy urban traffic areas, the rectangular tunnel boring machine (RTBM) method is further discussed to address the complex construction challenges. The research focuses on the selection of construction methods. The implementation details of the RTBM technique are analyzed, including the management and monitoring of the construction process. Furthermore, the special attention is given to environmental protection measures and safety management strategies to ensure the minimum impact of construction activities on the surrounding environment and personnel. Through a case study, the application of the RTBM method in busy urban traffic construction is presented in detail, which aims to provide the practical operational guidance and references for other similar urban infrastructure projects so as to more effectively plan and implement the similar street crossing constructions.