Abstract: In order to explore the microwave mobile heating effect of the semi-resonant cavity type of microwave heating machine, the heating effect of the semi-resonant cavity type microwave heating method and the radiation field type microwave heating method is compared by simulation, and the influence of the structure size of the semi-resonant cavity on the microwave mobile heating effect is analyzed. The results show that the semi-resonant cavity microwave mobile heating method has certain advantages in heating efficiency and heating uniformity, and changing the transverse spacing in the semi-resonant cavity structure will affect the heating uniformity and heating rate of asphalt mixture, which can provide technical basis for the design of heat regeneration products in microwave heating machine.