It is important for the extension project redesign of the petrochemical enterprise to reconstruct the 3D-modeling of the petrochemical devices. We use the 3D-scanning technology to realizing the reconstruction of petrochemical enterprise pipeline. Meanwhile, using the reconstruction model and the given extension project model, we can do the research on the collision detection. It will realize the accurate design work of the extension project through the collision detection. According to this approach, we study the method of the 3D-model reconstruction. Moreover, utilizing the VC++6.0 development platform and the software bag of OpenGL, we develop a system to accomplish the 3D pipeline model visualization and collision detection between the design model and the reconstruction model for the correction of the extension project.