In order to fabricate leather finishing materials with enhanced flame retardant effect, GO was prepared using natural graphite as raw material by modified Hummers method, and then it was reduced by NaBH4. The as-obtained graphene was characterized by FTIR, XRD and TEM, which show that graphene has been successfully prepared. Then, physical blending method was used to introduce graphene into natural protein casein system to prepare casein-based composite emulsion applied as leather finishes. The flame-retardant property, mechanical property, as well as dry and wet rubbing resistance of the finished leather samples were tested. The results show that when the rGO content was 0.5% of the solute quality of the casein system, compared with the casein system without rGO, the combustion rate of the leather samples decreased by 47.2%, the limit oxygen index (LOI) increased from 24.2% to 26.3, the heat release rate (HRR) decreased by 53.1%, and the total heat release rate (THR) also decreased. At the same time, the introduction of graphene has little effect on the mechanical properties, as well as dry and wet rubbing resistance of finished leather samples.