Abstract: In order to solve the problem of high performance absorber in infrared field, a broadband infrared absorber based on metamaterial is proposed in this paper.Based on the three-layer structure of "metal-media-metal", the magnetic absorber realizes the broadband absorption in the infrared (10.0-12.7 THz) band range by designing the metal pattern printed on the upper layer of the dielectric substrate, and the relative bandwidth with the absorption rate of more than 90% reaches 23%.In this paper, the effects of different size parameters of the absorber on the absorptivity are analyzed, and the equivalent permittivity and the equivalent permeability of the absorber are obtained by S parameter inversion method. Meanwhile, the absorbing mechanism of the absorber is analyzed by using the equivalent medium theory and interference elimination theory.In addition, the designed absorber has the advantages of insensitive polarization, high absorptivity, low profile, and stable operating bandwidth within a certain range of incident angle.