In order to optimize the thermal characteristics of CNC forming gear grinding machine YK73200 and reduce thermal deformation,a thermal characteristic model of the gear grinding machine was established,and the model was verified by experiments.The corresponding thermal structural optimization and high efficient cooling measures were put forward on the weak links of machine tool.The thermal characteristics of the improved machine were analyzed based on the model.The results show that based on the symmetrical design principle of thermal structure,the thermal deformation of the key points of the gear grinding machine can be reduced by 21.3% in different machining position by improving the structure design of cooling channel of bed.