CNC systems have been widely adopted in the modern manufacturing and most of them were built on computers. As a result of the special hardware and software, it is difficult to maintain the CNC systems and update them. To solve the problem above, many new methods were adopted. One method based on DSP is studied in this paper. The features of new generation CNC based on DSP were presented and characteristics of DSP were introduced. Details about how to complete the design of hardware and software were discussed. By using the pipeline structure of DSP, rapid coding can be done. Dual-CPU architecture is adopted in this paper. And by combining DSP, host computer and some other peripheral equipment, the whole CNC system can be constructed. Meanwhile the control methods to realize the position closed-loop and speed closed-loop are given.