For the features and requirement of high-speed, high-precision, flexibility of modern CNC (Com-puter numerical control) machine, combined efficient data processing DSP (digital signal proces-sor)capabilities with high-speed, parallel processing and reconfigurable characteristics of FPGA (Field Pro-grammable Gate Array).We designed a two-stage interpolation control system by using the DSP to do the rough interpolation, then FPGA finish the accurate interpolation. Using the Bezier algorithm in three-dimensional CNC machining, and achieve any curve trajectory in space, expand the CNC trajectory from two-dimensional space to three-dimensional space and achieve high accuracy and good reliability, reduce sys-tem costs by combining with the use of DSP and FPGA .The system has a good computing ability, flexible architecture, good modular design, strong real-time, scalable and versatile features.