By analyzing the characteristics of Archimedes spiral equation, this equation takes the included angle as the variable, and the algorithm of equal included angle straight line approximation can be used to calculate the interpolation points. Using the advantage of parametric programming by FANUC system macro program, a G instruction(G102) is customized to realize the machining of Archimedes spiral surface. This G instruction is used in the same way as the system’s inherent G code, similar to a custom fixed loop code. It is different from the program number that G code must indicate when calling macro program. The G102 code can complete the machining of Archimedean spiral surface only by assigning values to each letter according to the format specified in the text. After processing verification on GLU28x40 CNC, the use method of customized G code is as flexible and convenient as the fixed cycle G code provided by CNC. It can process Archimedes spiral profile that meets the requirements, and use the equal angle straight line approximation algorithm for interpolation. The calculation speed is fast, which effectively improves the processing efficiency of the profile.