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The surface settlement and deformation caused by shield launching construction of small radius curved tunnel is complex, and its settlement and deformation prediction is always a difficult problem. In this paper, combined with the actual project of Changzhou metro, based on the method of numerical simulation and regression analysis, the surface deformation law and key technology of small radius curve are studied. The results show that the modified Peck formula can well describe the surface deformation law of shield when the small radius curve starts in water rich sand layer, and can effectively predict the surface settlement value. The initial excavation speed of shield is generally 10—15 mm/min, the actual earth pressure is generally 1—1.25 times of water and soil pressure on the excavation face, and the grouting pressure should not exceed 0.3—0.4 MPa. The shield attitude adjustment device can achieve the purpose of accurate deviation correction when launching. The conclusions can provide reference for the construction of small radius curve of shield. [ABSTRACT FROM AUTHOR]