Assembly data is an important part of production design of the ship piping system. For the caculation of piping spool, large quantity and complex form leads to low efficiency and error-prone manual processing. Based on feature analysis of piping spool 3D model, using the divide-and-conquer method to construct a mathematic?model, by means of decomposing the complex piping spool into similar substructures, the goal of calculating assembly data automatically for any form of piping spool was eventually granted.Through independent development, the method has been successfully applied on the 3DEXP platform, effectively supporting the design and building of multiple types of ships. The research is significant for further?exploration?of digital?design?and?manufacturing of ship piping systems.