介绍了空间圆弧进给指令格式 ,在深入分析插补预处理的基础上 ,给出了插补控制算法 .使用具有空间圆弧插补能力的数控系统进行空间圆弧加工时 ,不仅简化了输入的数据量 ,同时能够使刀具从一点平稳地运动到另一点 .根据该算法编制的数控系统软件已成功应用于五轴数控机床 ,实践表明该算法具有可行性和可靠性 This paper introduces the format of circular arc feed instruction, and on the basis of deeply analyzing the interpolation preprocessing, gives the interpolation control algorithm.When using the numerical control system with space arc interpolation capability to do the arc machining, it not only simplifies The amount of data input, while enabling the tool from a smooth movement to another point.According to the algorithm of numerical control system software has been successfully applied to five-axis CNC machine tools, the practice shows that the algorithm is feasible and reliable