In order to study the influence of oil-air lubrication parameters on the thermal characteristics of high-speed electric spindles, the thermal characteristics orthogonal test was carried out considering the two factors of air flow pressure and oil supply. The results show that the oil supply has the largest influence on the temperature rise index, followed by the airflow pressure, and the interaction between the two factors has a relatively small influence on the temperature rise index. The optimal level combination was obtained and the thermal deformation of the electric spindle in different directions under different levels of combination was obtained. By analyzing the reasons of different thermal deformation of electric spindle in different directions, it is concluded that the thermal deformation in Z direction should be controlled in the actual machining.