Aiming at the problem of machining inefficiency caused by narrow path interval in the current five-axis CNC machining process of triangular mesh surface, a tool path generation algorithm for variable path interval in machining was proposed. Firstly, with the data reconstruction of triangular mesh, an intersection-algorithm based on KdTree mesh partition was proposed, which achieved fast grid data point acquisition. Then, with analyzing the geometric characteristics of the toroidal cutter and the triangular mesh surface, a method was proposed to maximize the effective cutting radius by changing the tilt angle and optimizing the inclination angle under the condition of no curvature interference. Finally, a discrete model of toroidal cutter was established based on the characteristics of triangular mesh surface, and the corresponding interference detection and correction method was also put forward. The simulation results showed that the optimization method of path intervals can significantly improve the machining path intervals compared with the existing methods under the same machining conditions and the presented method of checking and correcting the tool-interference can effectively avoid the local interference of cutter bottom and the global interference of cutter arbor. It can be seen that the methods proposed had upper theoretical significance and practical application value in improving the efficiency of five-axis CNC machining for triangular mesh surface.