A method for preparing a film bulk acoustic wave device by using a film transfer technology comprises: 1) providing an oxide single-crystal substrate (1); 2) implanting ions from an implantation surface (11) into the oxide single-crystal substrate (1), and then forming a lower electrode (2) on the implantation surface (11); or forming the lower electrode (2) on the implantation surface (11), and then implanting ions from the implantation surface (11) into the oxide single-crystal substrate (1); 3) providing a support substrate (3) and bonding a structure obtained in step 2) with the support substrate (3); 4) peeling off part of the oxide single-crystal substrate (1) along a defect layer so as to obtain an oxide single-crystal film (14), and transferring the oxide single-crystal film (14) and the lower electrode (2) to the support substrate (3); 5) corroding the support substrate (3) to form a cavity (5); and 6) forming an upper electrode (41) on the surface of the oxide single-crystal film (14). Provided is a
