Based on ergonomics, a virtual appearance design was carried out for the shields of the NC machine tool SSCK40. The whole design process was completed by such softwares as AUTOCAD, SolidWorks and PhotoShop for 2-D drawing, 3-D modeling and the entire appearance design of the NC machine tool, respectively. The virtual design process proposed is proved available to shorten the R&D period of new products and decrease production cost, thus enhancing the competitiveness of the NC machine tool on market.