To reduce the error of CNC machine tools, the following methods can be adopted:

1. Optimize the structure of the machine tool: choose a machine tool structure with high rigidity and high stability, and use precision guide rails, screw drives and other components to improve the rigidity and stability of the machine tool.
2. Calibration and adjustment: Calibrate and adjust the CNC machine tools regularly, including calibration of positioning errors, angle errors, and straightness errors. Ensure the accuracy and consistency of each axis of the machine tool.
3. Optimization of the numerical control system: select a high-precision and stable numerical control system, and perform appropriate parameter setting and calibration. Ensure the precision of CNC system, the accuracy of interpolation algorithm and feedback control.
4. Optimization of the servo system: select a high-precision, fast-response servo system, calibrate and adjust the feedback device of the servo system, and ensure the accuracy and stability of the servo system.
5. Optimization of the cutting tool system: select high-quality cutting tools, maintain the geometric accuracy of the cutting tools, regularly grind and replace worn cutting tools, and reduce the impact of cutting tools on machining accuracy.
6. Optimization of workpiece clamping and clamping methods: choose appropriate fixtures and clamping methods to ensure the stability and accuracy of workpieces. Pay attention to the rigidity, symmetry and stability of the fixture, and design the clamping scheme reasonably.
7. Control processing parameters: Reasonably select and optimize processing parameters such as cutting speed, feed speed, and cutting depth to avoid adverse effects on precision caused by excessively high or low parameters.
8. Environmental control: pay attention to controlling the temperature, humidity and vibration of the working environment of the machine tool to avoid the influence of environmental factors on the accuracy of the machine tool. Appropriate environmental adjustment measures can be taken, such as installing temperature control equipment, shock absorption measures, etc.
9. Training and technical improvement: train operators, improve their operating skills and adjustment capabilities, so that they can operate machine tools correctly, find and solve problems in time, and improve the machining accuracy of machine tools.

In short, to reduce the error of CNC machine tools, it is necessary to optimize machine tool structure, calibration and adjustment, optimization of CNC system and servo system, optimization of tool system, optimization of workpiece clamping and clamping methods, control of processing parameters, environmental control and personnel training. and other aspects for comprehensive consideration and improvement. Through these measures, the machining accuracy of CNC machine tools can be improved.