The invention discloses a method for synthesizing a graphene film material, comprising the following steps: a grapheme film is grown on a copper substrate under mixed atmosphere of hydrogen and methane by using a chemical vapor deposition method; then the copper substrate grown with the grapheme film is placed flatly on a silicon substrate with the oxidized surface, the obtained silicon substrateis placed into a ferric nitrate solution, the copper substrate is dissolved, and at the moment, the graphene film is deposited on the silicon substrate; then, the solution is diluted, then the silicon substrate deposited with the grapheme is taken out of the solution, and is dried in a vacuum drying oven; and after ultrasonic cleaning is carried out on the silicon substrate deposited with the graphene, and the obtained silicon substrate is placed in an annealing furnace communicated with argon for protection to anneal, thus a high-quality grapheme sample is prepared. By utilizing the method for synthesizing the graphene film material, the original complex steps needed for preparing the graphene film are simplified, a toxic agent needed by a chemical method is avoided, and the production efficiency of the graphene film is improved, thus by measurement of a Raman spectrometer, the prepared graphene film is proved to have good performances and excellent reliability.