A kind of architecture of open CNC system based on component technology was introduced by importing the theory of software engineering for realizing its characteristics of portability, expansibility and interchangeability and etc. The theory and realizing technology of component technology have been introduced. The software design of the system adopted a double-level by using the model of CORBA components. A star communication mechanism has been used to build the organization among the components and the method of communication. A simulation experiment of 3-D curve machining location on the self-developing hybrid virtual axis polishing machine tool was produced to prove that the CNC system based on this architecture has good openness and dynamic performance.