Abstract:Thermal error is one of the main error sources in CNC machining, and it has a great influence on the machining accuracy of parts. The thermal error compensation of CNC lathe can effectively improve the machining accuracy of machine tools. The temperature of the key points in CNC machining was realtime measured by platinum resistance temperature sensor. And the thermal error model was established by means of the fit of the measured temperature and linear regression theory. According to the thermal error model, the experiment of thermal error compensation was conducted, and it was proved that the technique is reliable and effective.