When an infrared wave is incident on the traditional epitaxial blocked impurity band detector, part of wave energy would be reflected by the device due to its special structural design and the properties of the constituent materials. The energy loss is obviously detrimental to the performance of the device. Here, a kind of bilayer metasurface-based microstructure array is introduced into the epitaxial blocked impurity band infrared detector for suppression of reflection. Experimental results show that the reflectance of the proposed metasurface-based device is lower than 20% in the wavelength range of 25.3～32.2 μm, particularly, which is even less than 3% at the wavelength of 30 μm. Meanwhile, the proposed metasurface antireflection coating also has strong polarization selectivity for incident wave, which meets the requirement for the fourth-generation focal plane arrays development.