Abstract: Radar waves incident on stealth structures excite surface traveling waves. Surface traveling waves encounter discontinuities such as protrusions, gaps, or steps, scattering occurs, degrading stealth performance. Existing surface wave attenuation structures suffer from issues like large thickness and weight, narrow absorption bandwidth, and difficulty in conformal application, making it challenging to balance the requirements of surface wave propagation control and efficient attenuation. This paper studies the relationship between the geometry of the metamaterial unit and the dispersion characteristics of surface waves. By altering the unit's structural dimensions to adjust the overall impedance of the metamaterial, wavevector matching is achieved, resolving the mismatch effect induced by differences between the absorber structure and the surface wave dispersion properties. After wavevector matching, the surface wave attenuation constant is adjusted by changing the resistance value of the top-layer ITO in the metamaterial to achieve attenuation. The designed metamaterial structure achieves good surface wave attenuation within a broad frequency range of 10–18 GHz. Furthermore, the designed metamaterial absorber utilizes flexible dielectric materials, with a structural thickness of only 1.2 mm. It can conformally adhere to the surface in front of electromagnetic defect structures prone to induce traveling wave scattering, attenuating the propagating surface waves.