The invention belongs to the field of material preparation and discloses a method for preparing a hafnium oxide based ferroelectric film by adopting reaction magnetron sputtering. The method comprisesthe following steps of: firstly removing residual impurities and dirt on the surface by adopting a standard RCA washing process; subsequently, by taking metallic hafnium and a doped single metal or nonmetal as a target material, depositing an amorphous hafnium oxide based film in a mixed atmosphere of Ar and O2 by adopting reaction magnetron sputtering; and afterwards annealing and crystalizing the deposited film to obtain the hafnium oxide based ferroelectric film which is of an orthorhombic-phase Pca21 spatial group crystal structure. The method for preparing the hafnium oxide based ferroelectric film by adopting reaction magnetron sputtering disclosed by the invention has the advantages that the deposition speed is high; the temperature of base materials is low; damages of the film layer are small; the film and a substrate are combined well; the film is high in purity, good in compactness and good in film formation uniformity; a sputtering power supply is flexible to select; the doped elements are flexible and versified in selection; cooling of the target material has no special requirements; the process is good in repeatability; the film growth conditions are easy to control;and the method can easily realize industrialization.