Aiming at the problem of data barriers between two-dimensional drawings and three-dimensional models in the design of ship piping systems, by analyzing the design characteristics of two-dimensional piping system principle diagrams and the design requirements of three-dimensional modeling, the driving rules of two-dimensional and three-dimensional integrated design are studied. By embedding the two-dimensional and three-dimensional integrated design rules in the piping system integrated design tool, a design data integration system is constructed to reduce the differences between two-dimensional and three-dimensional, and achieve the integrated design of two-dimensional principle diagrams and three-dimensional models of the piping system. Through practical examples, it is verified that the integrated design of the piping system ensures design accuracy and improves the efficiency of ship design.