Taking one shield tunnel crossing through the bridge viaduct pile foundation of a metro as the engi- neering background, this study analyzed pile underpinning and removing technology of the shield tunnel crossing in such a complex environment. It solved the technical difficulties in the process of underpinning, such as wa- ter-proof performance, stability of structure and tool modification of cutter head. At the same time, the construc- tion process of underpinning pile was simulated by plane strain calculation model. The results show that the maximum settlements of bridge piers and underpinning pile were all in the scope of the early warning, the con- ditions of this underpinning pile engineering were very complicated and the displacement control was very strict. Through the research and analysis of the construction scheme, it proves that the construction method is feasible with a high standard, which can provide certain engineering reference for similar projects.