Abstract: A two-layer orthogonal low-pressure plasma array is proposed. The numerical simulation and experimental methods are used to analyze the influence of the plasma electron density and structural parameters for the array on the reflection characteristics of the target in the X-band range and vertical polarization. The results show that electromagnetic wave resonates with the orthogonal plasma array, resulting in a great attenuation at the resonance point. To change the layer spacing of the plasma array may excite different resonance modes, so that multiple resonance frequencies appear at the reflection curve under the same layer spacing. The simulation and experimental results show that the attenuation peak moves to the higher frequency with the plasma electron density rising,while the increase of the layer spacing of the plasma array makes the attenuation peak move to the lower frequency.These results can provide a reference for the design and application of the plasma periodic structure.