The invention discloses a method for preparing a BZN thin film for an embedded type capacitor, comprising the following steps of compounding, ball milling, presintering, molding, sintering, depositing thin film and hot treatment. The deposited thin film is a thin film the thickness of which is 200-500 nm and is prepared by depositing a prepared BZN ceramic target material on a Pt plating substrate or copper-clad plate with a polymer base in situ by adopting a pulse laser depositing technology. The thin film prepared adopting the pulse laser depositing technology and the in-situ depositing method at room temperature presents an amorphous BZN material, the surface of the thin film is very smooth and has lower roughness. The dielectric constant of the BZN thin film material prepared by using the method is 60, and the loss is about 0.6 percent. In 0.3 MV/cm, the density of leakage current is 1*10-7A/cm2, thereby the use demands as a dielectric material of the embedded type capacitor are sufficiently satisfied. The amorphous BZN thin film material has simple process and satisfies the demand of rapid development of electron components, thereby having good market prospect.