Abstract: The application of Chebyshev ridge structure in the optimization of absorbing materials in microwave anechoic chambers is discussed, and the influence of Chebyshev ridge structure on the reflectivity level of the quiet region of the microwave anechoic chamber is analyzed by using geometric diffraction theory. The simulation results show that the installation of the Chebyshev absorption ridge structure in the first Fresnel region of the microwave anechoic chamber can significantly reduce the reflection level in the stationary region, and the reflection level and taper degree of the measured quiet region in the anechoic chamber built by this scheme meet the far-field test conditions of the antenna. The research results provide a theoretical basis and practical reference for the design and application of high-performance microwave anechoic chamber absorbers.