In this paper, the technologies for shield boring underneath existing buildings from Grand Theater station to Ludan Village station of Shenzhen Metro is determined on basis of studying on relative technologies in China and abroad, so as to guarantee safe shield boring and avoid adverse impact on the existing pile foundations. The practicability of the construction technologies is theoretically analyzed, and the details of the construction technologies are determined. The construction technologies, including ground consolidation, trial boring, shield modification and ground surface secondary grouting, are summarized. In the end, the shield has crossed underneath the buildings successfully, and the safety of the buildings has been guaranteed.