The construction of connected aisle in the tunnel between Dengshikou station and Dongsi station on metro line 5 in Beijing is presented. Due to the high underground water level and complicated geological situation, the mining method was adopted to construct the aisle. The construction principle “The strong support, the triplepipe injection in advance, the vacuum dewatering, and the section excavation” has been performed. Moreover, monitoring and waterproofing in construction are discussed in this paper, which can be reference of other similar construction.