An approach of three-axis NC cutter path generation for √3 subdivision surface is proposed. A computing formula for error estimating √3 subdivision surface is derived. Using the formula, one can predict how many steps of subdivision are necessary to meet a user-specified tolerance without subdivision the meshes actually. Tool path planning is generated automatically based on cutter location surface. A collision detection and avoidance is developed for the interfere-free. The generated tool paths comply with a certain tolerance and surface finish specified on the surface. We implement our approach and present results. Our approach reduces the computational complexity and is robust efficiently