The mathematical development of structural topology optimization provides a mature tool for design optimization, although the application is still very limited in engineering practice. This paper intends to study the application of topology optimization in industrial design via commercial CAD software interfaces. An innovative numerical procedure for this purpose is introduced based on convenient CAD modeling interfaces. As an instance, the B-spline based environment Rhinoceros3D features the modeling module for the optimization procedure, in collaboration with an additional optimization engine BESO3D. The topology optimization is realized based on the CAD model from Rhinoceros and outputs the optimal solution into Rhinoceros after computation. Further interpretation of the optimization results is discussed within the framework of Rhinoceros. Design applications of the modeling-optimization design integration are showcased as the examples to demonstrate the efficiency and robustness of topology optimization in industrial design.