Abstract: Collision detection is a key technology in interactive virtual assembling operation. A new rapid collision detection algorithm for interactive operation in virtual reality (VR) environment was presented. It is an improved method of the conventional BV hierarchies method. According to the algorithm, a new method is used to compute BV hierarchies using regions partitioning on a polygonal model and a rapid overlapping check between facets and a BV. According to user’s operation collision detection pairs are determined; a parallel method based on PCs and Local Area Net (LAN) is developed to detect the collisions among many virtual objects. A method for dynamically modification hierarchies is developed for detecting overlapping between two BV hierarchies models. The performance of the algorithm is verified by means of an automobile underchassis assembling. The result shows that the method is applicable for all general polygonal models and can detecting overlapping during realtime simulation.