The invention discloses a thermal management material, a preparation method thereof and an application. The method includes the steps: in weight percentage, slowly adding 5-10% of multilayer flake graphene and 2-5% of carbon fibers into 60-80% of molten long-chain alkane, and uniformly stirring mixture to obtain initial phase-change materials; adding 2-5% of flame retardants into the initial phase-change materials to uniformly stir to obtain phase-change materials of compound flame retardants; mixing 5-10% of reinforced resins and 5-10% of oil-absorptive resins to heat to a molten state, adding the phase-change materials of the compound flame retardants, continually stirring for predetermined time, and cooling the mixture to obtain the thermal management material. The thermal management material prepared by the method has high flame resistance, insulation performance, high-thermal storage performance and heat-conducting performance, the thermal management material contacts with the surface of a new-energy power lithium battery, good heat-conducting effect can be achieved, heat storage effect can be also achieved, heat moment rising of a lithium battery pack is solved, thermal runaway risks are reduced, and safety of the battery pack is improved.