The invention relates to a construction method for tunnelling a small-radius curve segment of a tunnel through a shield method, comprising the following steps of: (1) designing a shield machine and a duct piece; (2) ensuring the shield machine to be pushed along a design axis by controlling the value of the elevation of a notch plane of the shield machine in the construction pushing process of the shield machine, and particularly correcting deviation before the shield machine is pushed into the extra-small-radius curve segment; and (3) splicing the corresponding duct pieces into the tunnel byadopting a standard curve ring and a small-ring width linear ring of appropriate wedge quantity, which are selected according to a calculated deviation connecting quantity value in the step (1), on the extra-small-radius curve segment on the basis of the shield machine tunnelling along the design axis of the tunnel. The construction method can realize that a shield can well control the design axis of the tunnel in the whole tunnelling process of the small-radius curve segment and ensure that the duct pieces and the shield are not jammed, and a curve at the small-radius curve segment is easement.