Aiming at the problem of low prediction accuracy of fluctuating thermal deformation modeling caused by the transmission gap caused by the inherent spindle feed system structure of CNC gear shaper,a modular modeling method based on mean smoothing processing fluctuations was proposed.Fuzzy clustering combined with gray correlation degree method and multiple linear regression were used to establish thermal error compensation model for the x and y directions of the machine tool spindle,and the probabilities of the predicted residual value in different distribution ranges were calculated.The results show that compared with the traditional thermal error modeling method,the modular prediction residual value is more evenly distributed in different ranges,and the robustness of the proposed method has been effectively improved,which provides reference for thermal error modular modeling method.