The invention discloses a method for preparing a vanadium oxide film by a metal oxidation method, which comprises the following steps of: (1) preparation of a silicon wafer with an Si3N4 layer; (2) preparation of a pure metal vanadium film, wherein the vacuum degree is (5-6)X 10<-4>Pa, the sputtering working pressure is between 1 and 2.0 Pa, and the sputtering time is between 10 and 20 min; and (3) annealing oxidation, wherein the annealing temperature is between 400 and 500 DEG C, and the annealing oxidation time is between 1and 2 hours. The invention provides the method for preparing the vanadium oxide film by the metal oxidation method with easy control and simple process, the resistance temperature coefficient of products reaches more than -3X10<-2>K<-1>, and preparation methods of thevanadium oxide film are developed. The vanadium oxide film is an ideal material for producing heat-sensitive sensors, infrared detectors and infrared imaging devices.