To realize smooth manufacture of product with complex surface, a new algorithm, design for quality control (DQC), strongly connects design model and machining model. Geometry information in popular STL file in design industry was fast obtained and then exactly input into a grid-meshing model. For meeting precision requirement of machining model, quality-control parameter was employed to control subdivision times and the result-surface machining quality. Then the designed features of aesthetics surface or functional surface were kept in smooth manufacture with optimum quality. By self developed software for DQC in Visual C++, stability and reliability of this algorithm were proved.