The invention discloses a method for preparing gold nanoparticles by annealing of a gold film. The method comprises the following steps: depositing a gold nano film (2) on a base material (1) by a magnetron sputtering method or vacuum evaporation method, wherein the vacuum degree of a magnetron sputtering chamber or a vacuum evaporation chamber is 10<-3>-10<-4>Pa, and the thickness of the deposited gold nano film (2) is 5-20nano; integrally arranging the deposited gold nano film (2) and the base material (1) in an annealing furnace to be heated for 30-120min, wherein the heating temperature is 350-600 DEG C; and cooling to the room temperature, and forming gold nanoparticles (3) on the base material (1). According to the invention, through controlling the thickness of the gold film, the annealing temperature, the annealing time and other parameters, the gold nanoparticles in different sizes and shapes can be obtained. The method disclosed by the invention has the advantages that the preparation is simple, the sizes and the shapes of the nanoparticles can be controlled, the preparation efficiency is high, and the like.