▎ 摘　　要

We present a theoretical study of the magnetic field dependence of the nonreciprocal absorption effect for composite microstructure. We analyses and summarizes the relevant conductivity calculation models of graphene, and discusses and compares the electrical conductivities and dielectric constants of graphene based on different theoretical models. Moreover, the external magnetic field applied model and the non-magnetic field applied model are compared in details, the most suitable calculation model has finally chosen. And the influence of the chemical potential on the refractive index of graphene was compared and discussed under the condition of an external magnetic field. Furthermore, we propose a nonreciprocal effect enhanced magneto-optical composite microstructure using graphene and analyze the effect of grating height, grating filling ratio, incidence angle and magnetic field intensity on the nonreciprocal absorptance, in this work. It is found that graphene can effectively enhance the nonreciprocity phenomenon in the wavelength range, and the absorptance can also be greatly improved.