The invention belongs to the technical field of antirust materials, in particular to a preparation method of composite antirust material. The preparation method takes di-n-butylamine, carbon disulfideand sodium molybdate as raw materials; as a modified fluorocarbon emulsion has better cohesiveness and can firmly adhere to the surface of a metal substrate, thereby achieving preliminary antirust effect; secondarily, a sulfur-containing organic molybdenum compound has excellent pressurized anti-wear performance and can protect a metal surface effectively, thereby solving the problem of poor antirust effect of traditional antirust materials; sodium carbonate and carbon nanotubes are also added into the antirust material disclosed by the invention, thereby improving the corrosion resistance and further the rust resistance of reinforcing steel bars; in addition, after curing, the antirust material can form a dense antirust membrane layer with fluorine-carbon macromolecules and graphene crosslinked and with hydrophobic effect, thereby preventing the phenomenon that water molecules enter the surface of the metal substrate and generate electrochemical reaction of gold dissolving and oxygenuptake, and inhibiting the corrosion of the metal substrate. The preparation method has a broad application prospect.