Shield machine is main equipment -5 in metro tunnel construction and the pipe segments on it, as a permanent lining of the metro tunnels, has a wide application, and therefore, model selection of the pipe segments has a direct effect on the accuracy and quality of metro tunnels. Based on the characteristics of the pipe segments, this thesis will focus on wedge calculation of isosceles trapezoid bend segment ring, pipe segments arrangement calculation and model selection basis of shield machine pipe segments, and work out the maximum bend radius of the pipe segments often used, which will direct model selection of pipe segments and organization of pipe segments production.