The invention discloses a dodecagonal segment for shield tunnel construction. Two long bevel edges which are both splayed are arranged on the edges of the two transverse ends of the dodecagonal segment, a long transverse edge, a short bevel edge, an inwards-sunken transverse edge, a short bevel edge and a long transverse edge are sequentially formed from one end to the other end of the edge, with a greater transverse length, in the edges of the two longitudinal sides of the dodecagonal segment, a short transverse edge, a short bevel edge, an inwards-sunken transverse edge, a short bevel edge and a short transverse edge are sequentially formed from one end to the other end of the edge, with a smaller transverse length, in the edges of the two longitudinal sides of the dodecagonal segment. The invention also discloses a segment lining structure assembled by dodecagonal segments, and the adjacent dodecagonal segments are embedded and limited. According to the dodecagonal segment with a specific shape, the shape has a mounting guide function, so that the segment can be easily positioned; the dodecagonal segment lining structure can be continuously tunneled and spliced, so that the construction efficiency and the overall lining rigidity are remarkably improved.