Graphene-based composite materials have broad application prospects in infrared detection stealth, but how to improve its broadband omnidirectional infrared absorption characteristics is still lack of systematic research work. In this paper, a binary graphene-based composite micro-nano infrared absorber with alternating distribution of optical medium layer and graphene layer is designed, and its infrared absorption characteristics are systematically studied by transmission matrix method. The results show that the resonant coupling effect of gain and loss can be generated in the structure by adjusting the number of graphene layers and the structure. The absorption rate is higher than 80% in the whole band of 8-14 μm, higher than 90% in the band of 10.0-13.3 μm, and the maximum bandwidth is 3.3 μm. In addition, the micro-nano structure exhibits polarization insensitivity of infrared absorption in wide angle range (0°-60°) with oblique incidence. The results of this study provide a new idea for the design and application of a new generation of graphene-based flexible wide-band and large-angle tunable infrared absorption micro-nano structure, and also provide a feasible technical method and realization path for a new generation of flexible lightweight stealth or camouflage film materials.