The CNC System with standardization HMI, mostly presents the same kind of form and cannot meet customer and dedicated CNC System's special requirements. Based on the analysis of the user interface customization demand, this paper designs a visual secondary development platform for the CNC System HMI based on Qt Graphics View Framework and model/view architecture. Firstly it registers components to platform and binds the corresponding property objects by using the object oriented secondary development method then completes the interface customization through the parameterization. Finally it uses the XML file as the configuration file to describe the graphical interface and transfer data between platform and CNC System. The secondary development platform mainly includes two modules which are PC configuration platform and NC analytic platform. The experimental results show that the platform has achieved good results in the special customization and reuse of CNC System's HMI, and the development efficiency of HMI is improved.