In order to accurately obtain the dynamic characteristics of double involute gears (DIGs), according to the characteristics of tooth profile engagement, a tribo-dynamic model of DIGs with multiphysics coupling characteristics is proposed by integrating the thermal elastohydrodynamic lubrication (TEHL) model, the temperature field analysis model and the dynamic model. The influence of different factors on its dynamic behaviors and the difference in dynamic characteristics between DIGs and common involute gears (CIGs) are comparatively analyzed. The results show that the thermal effect and tooth friction can intensify the dynamic response of the gear transmission. The variation of rotational velocity and torque has a significant impact on the dynamic behaviors of DIGs, the change of tooth waist order parameters have little effect on its dynamic characteristics, and the dynamic characteristics between DIGs and CIGs exist difference, but the difference is not obvious. Additionally, the theoretical model is verified through experiments.