Abstract: Collision detection is an effective three-dimensional computer-aided design (CAD) program used in engineering constructions. Modern complex and large scale architecture leads to increased demand for collision detection algorithms of higher efficiency. Based on the two most widely applied pretreatments, i.e., spatial decomposition and spatial occupancy, an integrated and efficient accurate collision detection algorithm is proposed. Through testing and analysis, the proposed algorithm has shown higher efficiency than other algorithms, and the larger the number of models, the higher the efficiency. Furthermore, the integrated algorithm has proven, with effectiveness and robustness, to be able to address various project demands. Practical applications have shown that the proposed algorithm is applicable to construction, mechanical, electrical and plumbing engineering.