In order to meet the accuracy requirements of machine tools,a thermal error compensation method with sensor was proposed.The thermal error compensation principle was introduced in detail.Through test comparison and data analysis,the thermal error of machine tool was studied experimentally.According to the statistical data,the conclusion was drawn.The conclusion and method were applied to the numerical control system,the thermal error compensation module of the numerical control system was improved.The results show that the thermal error compensation method with sensor can be used to solve the accuracy problem caused by the thermal error of the machine tools.It is widely used in the quality inspection of machine tools