A strategy that setting ridge groove surface in the inner wall of the microwave reactor is proposed for improving the heating uniformity without losing heating efficiency. The influence of the different ridge groove structure parameters on the heating efficiency and uniformity of the microwave reactor is simulated by using the finite element method. The result shows that the ridge groove structure can effectively improve heating efficiency and uniformity of microwave reactor. Heating efficiency of microwave reactor reaches 98.75% after being simulated. When compared with the smooth cavity wall of the microwave reactor, the heating uniformity is enhanced up to 58.54%.