From the perspective of CNC Machining operation flow, numerical control machine tool processing can be divided into three major modules: programming, tool setting and automatic machining. Among them, programming and tool setting are preparatory work for machining operations. Whether the programming is correct, whether the selected cutting amount is reasonable, and whether the input of tool setting parameters is accurate will be manifested in actual machining. Therefore, in order to ensure the accuracy of numerical control machine tool processing operations, it is usually necessary to carry out trial machining to check whether there are problems in numerical control machine tool automatic machining. So how to prevent collisions during CNC machining? Through the following understanding: three look at the program numerical control machine tool operations are completed by the program command control, by checking the program statement and program name, find out the problems, timely correction. Two look at the workpiece coordinates screen will display the current tool machine coordinates, workpiece coordinates and other detailed information, when checking, pay attention to the screen value and the actual tool tip position, to ensure that the coordinate value between the two can be one to three look at the tool tip position numerical control machine tool processing, cutting operations are completed by the tool, so in the machine inspection, should focus on the position of the tool tip. Second, a single-segment numerical control machine tool has a single-segment SBL execution function. After starting this function, the single-chip microcomputer will automatically terminate the processing operation every time it completes a control program. The numerical control machine operator needs to manually start the next program to carry out the processing operation. Second, low magnification. By adjusting the speed adjustment knob of the numerical control machine tool, the feed speed of the tool can be reduced. Before the tool is processed, the position of the tool tip and the coordinate display value can be observed. If the two values are different, the equipment can be shut down in time to avoid collision problems.