A machine thermal mechanical coupling deformation modeling simulation method was proposed for CNC cylindrical grinding machine to realize the thermal force coupling simulation and analysis of the whole grinding machine from processing to thermal equilibrium process.The coupling influence law of the force load and thermal load was analyzed through the thermal load and force load calculation method in the processing of the grinder;the analysis and calculation of different boundary conditions of each component considering forced convection and natural convection were carried out,and the influence law of the coolant temperature and the ambient temperature on the deformation of thermal force coupling was analyzed by using the finite element,and the temperature distribution and deformation of the key components of the grinder in the direction of the error-sensitive direction were measured through experiments.The deformation direction of the measurement results are consistent with the simulation results,and the amplitude error is less than 10%,which verifies the validity of the thermal force coupling modeling method of the whole machine and provides theoretical and technical support for the compensation of machining errors.