The invention relates to the technical field of heat dissipation materials, in particular to a graphene heat dissipation film and a preparation method thereof. The method comprises the following steps: S1, mechanically crushing an artificial graphite film to obtain artificial graphite powder; s2, mixing graphite oxide in a solvent containing ammonia water, uniformly stirring, and carrying out primary stripping to obtain graphene oxide slurry; s3, mixing the artificial graphite powder, the graphene oxide slurry and a stripping aid, uniformly stirring, and performing secondary stripping to obtain mixed slurry; s4, defoaming the mixed slurry, coating the mixed slurry on a base material, drying, and stripping to obtain a graphene film crude product; s5, placing the graphene film crude product in an inert atmosphere, heating to a first temperature, and carrying out carbonization treatment for a certain time; s6, placing a product obtained in the step S5 in an inert atmosphere, heating to a second temperature, and graphitizing to obtain a graphene film; and S7, carrying out lamination calendaring treatment on the graphene film to obtain the graphene heat dissipation film. The heat dissipation performance of the material can be effectively improved, and the cost is reduced.