The invention discloses a preparation method of a gold triangular nanoparticle array and vanadium dioxide film composite embedded structure. The preparation method comprises six steps of cleaning of a sapphire substrate, preparation of a monodispersion SiO2 mask layer, preparation of a gold triangular nanoparticle array structure, preparation of a vanadium film, preparation of a vanadium dioxide film and preparation of a gold reflection layer. The prepared film consists of the gold triangular nanoparticle array, the vanadium dioxide film and the gold reflection layer; and through adjustment of the preparation sequence, the gold triangular nanoparticle array can be embedded in the vanadium dioxide film to realize adjustment of resonant wavelengths. A film preparation absorber has such advantages as wider adjustment of visible light-near infrared band resonant wavelengths, high absorption efficiency, simple structure and small size, and can be applied to such aspects as light detection, electromagnetic switches and sensors.