At present, due to the non-standard establishment of BIM model and problems in IFC file parsing, practitioners have some difficulties in obtaining connected components. For this reason, this paper proposes a search method for connected components based on the improved OBB bounding box collision detection algorithm. This method firstly obtains the location information of any two components, and then create a bounding box by using the OBB algorithm for the next progress of detection. If the size of the bounding box is larger than that of the component, the OBB level bounding tree of the component is constructed. Given an offset to the bounding box of one component, then the collision detection algorithm is used to detect whether the two components collide. In case of collision, the two components are connected components, otherwise they are disconnected components.