To meet the NC program design of mechanical parts for mass customization, this paper puts forward the systematic structure and information model of NC program design. On the basis of the NC program intelligent design system, Product Data Management (PDM) and CAD are integrated as the platform, then, the main NC program of part is obtained through putting the parameter document into the NC program intelligent design system from SML (Tabular Layouts of Article Characteristics). NC Meta-model program stock is founded by adopting the Meta-model idea, which is seen as the resource-stock for NC design. According to the customization need, the parameters are changed in SML, then, the Meta-model program stock is searched, the configuration and variant design are realized through distilling, increasing, deleting and modifying the sub-program. Finally, the customized NC code is obtained. The T6436 rotor-circulating part is applied to validate the theory in the paper. Results show the NC program design for mass customization improves the design efficiency and meets product customization.