The invention discloses a method for preparing an NbTi film by utilizing a magnetron sputtering method, which comprises the following steps of: (1) selection of a target material: selecting blocky NbTi with the purity of 99.9 percent as the target material of magnetron sputtering, wherein the mass ratio of pure Nb to pure Ti is 53:47, and putting the target material into a magnetron sputtering chamber; (2) substrate processing: sequentially washing a substrate with ultrasonic waves and acetone, and putting the substrate into the magnetron sputtering chamber after polishing; and (3) preparation of the NbTi film: regulating the sputtering air pressure, the sputtering current, the deposition rate, the substrate temperature and the distance from the target material to the substrate to prepare the film through sputtering for a certain time, wherein the vacuum degree of the magnetron sputtering chamber is smaller than or equal to 2*10<-5>Pa, and the working gas is argon gas. The NbTi film prepared by the invention has good superconducting characteristic and practical value, and meanwhile, the NbTi film provided with an AlN protective layer has further improvement on the superconducting characteristic compared with the NbTi film which is not provided with a protective layer.