With the progress of science and technology, the microwave oven has been widely used for heating and thawing, but there are still uneven heating conditions in microwave heating at present. This paper designs two-dimensional and three-dimensional heating simulation experiments, discusses the effect of the rotation angle of the rotating body on the electric field distribution in the cavity in the two-dimensional simulation, and verifies it in the three-dimensional simulation. The results show that when the cross-rotary body rotates at 22.5 deg, the magnetic field distribution is more uniform, the heating average value is the highest, and the standard deviation is the lowest.