With the rapid development of building steel structure in recent years,the aesthetic appearance of plastic arts has been favored. In particular,the complex multi-curved structure in the structure of the venue requires high precision of the components,and it is difficult to process by conventional methods. In this paper,the structure of the special box with five-sided curved surface in xiangyang science and technology museum is taken as an example,and the process method is optimized from the aspects of component assembly and welding,and then the precision of components is systematically controlled to ensure that the processing of components meets the design requirements.