Laser tracker has widely been used in manufacturing industries, such as the industry of the large-scale machining tool, automobile, aircraft. So a high precision laser tracker is essential to satisfy the measuring requirements. In the paper the errors of laser tracker was analyzed and their calibration methods were discussed and studied. Then a calibration for laser tracker was carried on by using CMM and the measuring accuracy was verified. Finally, we demonstrate the application of laser tracker for detecting the large-scale machining tools. The measurement shows that the feeding straightnesses of tool rest in the two orthogonal directions are 0.0564 mm and 0.0309 mm in the working scope respectively. The results show the straightness of the body guide for the lathe meets the requirement, whereas the lathe tool workbench on the X axis direction does not and needs to be adjusted.