In the fine-pitch gear manufacturing process， significant thermal deformation is prone to occur during the gear hobbing， which in turn affects its dimensional accuracy and operational performance. Based on the principle of spreading processing and the mechanism of metal destruction， a thermal-mechanical coupling model is proposed for the intermittent hobbing of fine-pitch gears. Steel fine-pitch gear specimens are prepared using various hobbing speeds. By comparing the measured profile deviations with the simulated plastic strain values， the accuracy of the proposed model is verified. The influence of modulus， cutting speed， and heat transfer condition on cutting stress， temperature， and thermal deformation is studied. The results show that the cutting stress is negatively correlated with the gear modulus and positively correlated with the cutting speed. The tooth surface defect density， temperature， and thermal deformation are positively correlated with the cutting speed. To reduce heat deformation and improve tooth accuracy and surface quality， the rotational speed of the hob and its diameter should be decreased. Additionally， convective heat transfer in the cutting zone should be enhanced.