Abstract: Through settlement simulation analysis of the metro shield section undercrossing the municipal highway tunnel in the soft soil layer, combined with the actual engineering example of the Wuxi metro shield section closely crossing the Tai Lake Avenue tunnel, and targeting the characteristics of constructing metro shield section in waterrich sandy soft soil layer such as big disturbance to stratum,high crossing risk and obvious deformation, the key technology suitable for constructing the small radius curve shield tunnel undercrossing highway tunnel in water-rich sandy soft soil layer is explored. The technical parameters related to shield construction are determined.