Chemical pipeline figure usually contains a large number of valves and fittings, which are the difficult part of 3D reconstruction. Based on the study of simply connected chemical pipeline reconstruction, a method that replaced different valves or fittings with different color segments was proposed. This method helped identify and match pipelines more quickly and accurately, and completed the 3D reconstruction. The main content consisted of the information recognition and matched with the front view and a top view of the pipeline diagram, the storage and access of 3D information, and the study of application examples. The implementation was mainly conducted by using AutoLISP, which was the secondary development language of AutoCAD.