Owing to arithmetic speed’s influence of computer software, the accuracy and speed of numerical control system’s feed based on software interpolation are subject to certain restrictions. FPGA-based realization of four kinds of hardware circular interpolation algorithm in this paper, the hardware logic designed with verilog hardware description language, and the actual trajectory verified by ModelSim simulation and coordinate draw point; ARM+FGPA-based implementations of four circular interpolation algorithms do the verifications in two axes architecture automatic CNC machine tool. From the results, improved min-error interpolation has the best precision and efficiency among the four interpolations. So this interpolation algorithm has superior practical value on CNC machine tools and industrial robots.