Abstract: Constructing robot simulation system and calibrating robot end tools can improve robot machining accuracy and realize fast trajectory programming. In this paper, the mirror relationship between the actual robot system and the robot simulation system is used to calibrate the end tool of the robot. Firstly, a calibration probe was installed at the end of the robot to measure the position and pose of the cuboid calibration block of known size in the robot space, and the image model of the cuboid was established in the robot simulation system. Secondly, the position and pose of the tool model relative to the end of the robot model are adjusted under the condition that the position and pose of the tool model relative to the edge and face of the cuboid model are consistent with that of the tool model relative to the edge and face of the cuboid model, and the mirror relationship of the tool model in the two systems is established. Finally, a calibrated tool is used to measure the blank, and the image of the blank is built by the measurement matrix in the simulation system, and the tool path conversion is realized in the simulation system. The experimental and practical machining results show that the calibration method has the advantages of simple calibration process and high calibration precision, and the dislocation error of two-way through groove machining is less than 0.73 mm.