In order to realize the automatic calculation of assembly data of ship pipe segment in any form, a calculation method of ship pipe segment assembly information is proposed. Based on the important features of 3D model of pipe segment, a general mathematical model of pipe segment is constructed with Divide and Conquer, and the complex pipe segments are simplified as the similar substructures to calculate the pipe segment assembly information such as relative angle and relative distance. The method is successfully applied on 3DEXP, and the research results are of great significance in further exploring the digital design and manufacture of ship piping system.