Abstract: Molecular dynamics (MD) method was used to investigate the effect of the number of graphene nanosheets (GNs) layers and the number of sheets in each layer on the mechanical reinforcement of GNs/Al composite at different compression stages. The results show that the increase of GNs layers and the number of GNs sheets increases the enhancement effect of elastic modulus, yield strength and maximum stress strength of the composite. When the reinforcement layer is composed of 3 or more GNs sheets, double maximum stress peaks appear in the compression curve. At the late compression stage, the fracture of GNs results in the anisotropy of the composite, and the transverse deformation of the composite in the zigzag direction of GNs is larger than that in the armchair direction. When the thickness of metal layer is less than 3 nm, the confined layer slip model is not applicable.