Under the combined influence of the internal heat source and the external heat source, various parts of the CNC gantry will have different thermal deformations, which will directly cause the relative operating relationship between the workpiece and the tool to be destroyed. For CNC gantry, the occurrence of thermal deformation has a great influence, because the entire processing process is controlled by calculation instructions. In order to reduce the occurrence of thermal deformation, the CNC gantry structure generally uses the following measures to prevent it. 1) In order to reduce the main heat source of thermal deformation caused by internal heating, the heat source should be separated from the host as much as possible. 2) Improvement of the spindle box For the spindle box of the CNC gantry, the thermal deformation of the spindle should occur in the vertical direction of the tool as much as possible. This can greatly reduce the influence of the thermal deformation of the spindle on the machining diameter. 3) Improvement of CNC gantry components In the same heating environment, the components also have a large degree of influence on thermal deformation. 4) After a series of measures are taken to control the temperature rise to reduce the heat source, the thermal deformation will be improved. However, it is difficult or impossible to completely eliminate the internal and external heat sources of the CNC gantry. Therefore, it is necessary to effectively control the temperature rise through a good heat dissipation and cooling process, so as to reduce the influence of the heat source.