Abstract: Temperature can not be accurately measured and precisely controlled in micro-milling process. To this problem, from the point of the temperature, a finite element analysis model was built using the technology of arbitrary Lagrangian Eulerian adaptive grid and the method of thermo-mechanical coupling. According to actual micro-milling situation, the required parameters were reasonably set. It was combined with the important conditions that the cutting edge radius would become larger with the wear of micro cutter. Finally, the effect of temperature changes on the workpiece was numerically analyzed. The simulation results showed that the temperature changing trend of the workpiece in each thermal zone meets the actual temperature of the micro milling process. The results may have certain significance in practical micro-milling process.