The present invention discloses a method for growing gallium nitride based on graphene and magnetron sputtered aluminum nitride, and a gallium nitride thin film. The method according to an embodiment comprises: spreading graphene over a substrate; magnetron sputtering an aluminum nitrite onto the graphene-coated substrate to obtain a substrate sputtered with aluminum nitrite; placing the substrate sputtered with aluminum nitride into a MOCVD reaction chamber and heat treating the substrate to obtain a heat treated substrate; growing an aluminum nitride transition layer on the heat treated substrate and a first and a second gallium nitride layer having different V-III ratios, respectively. The gallium nitrate thin film according to an embodiment comprises the following structures in order from bottom to top: a substrate (1), a graphene layer (2), an aluminum nitride nucleation layer (3) fabricated by using a magnetron sputtering method, an aluminum nitride transition layer (4) grown by MOCVD, and a first and a second gallium nitrate layer (5, 6) having different V-III ratios.