The invention discloses a method for preparing a diamond film with an amorphous silicon dioxide intermediate transition layer. The method comprises the following steps: by taking a hard alloy as a lining and taking silicon-containing organic macromolecule precursor cracking as a solution, firstly obtaining the amorphous silicon dioxide intermediate transition layer film on the surface of the lining, and by taking a chemical vapor deposition method as a preparation solution, in situ depositing on the surface of the amorphous silicon dioxide intermediate transition layer to prepare the micron diamond film. By adopting the amorphous silicon dioxide intermediate transition layer prepared by the invention, the roughened surface shape of the hard alloy processed by a two-step method can be improved, the adhesive force of the diamond film and the hard alloy lining can be enhanced, the surface roughness of the diamond film can be reduced, the friction and wear properties of the diamond film can be improved, the service life of the diamond coating cutter is prolonged and the cutting performance of the diamond coating cutter can be improved.