The invention provides an epoxy resin composition which comprises a component A and a component B, wherein the component A comprises 80-100 parts of epoxy resin, 0-20 parts of a diluent and 1-3 parts of a thixotropic agent; the component B comprises 30-35 parts of a curing agent, 1-5 parts of an accelerant and 1-5 parts of a silane coupling agent; the silane coupling agent is an organic silane coupling agent with two or more amino groups. Meanwhile, the invention further discloses a preparation method of the epoxy resin composition, a fiber resin composite material and an aluminum/fiber/resin composite material. The invention aims to solve the problems that a resin system of the existing aluminum/fiber/resin composite material is not high in bonding strength and can cause environmental pollution, the high-strength connection between the aluminum/fiber/resin composite materials under the normal temperature or low temperature curing conditions can be achieved, and the requirement on the complexity degree of a surface treatment process of an aluminum profile is reduced.