Abstract: CORDIC is an efficient algorithm that plays an important part in various engineering applications.Method based on traditional CORDIC algorithm is introduced.By increasing the number of bits of inner phase accumulator and using two bits to represent directional control factor, a sine and cosine generator is designed based on FPGA.The result of QUARTUSⅡshows that the design is feasible.Finally, the phase resolution and error performance is analysed by using MATLAB, the results demonstrate that this optimization design can improve the performance of CORDIC effectively.