The invention belongs to the field of piezoelectric film materials, and particularly relates to a preparation method of an AlN/ZnO/InGaN/diamond/Si multilayer-structure surface acoustic wave filter. The method comprises the following steps: cleaning an Si substrate, sending the Si substrate into a hot-wire chemical vapor deposition reaction chamber, depositing a diamond film with the thickness of 100-300nm on the Si substrate, sending the substrate into a metal organic compound chemical vapor deposition reaction chamber, introducing trimethyl indium, trimethyl gallium and nitrogen gas into the reaction chamber, depositing an InGaN film with the thickness of 20-100nm on the diamond/Si substrate, simultaneously introducing argon carrying diethyl zinc and oxygen into the reaction chamber, depositing a ZnO film with the thickness of 20-100nm on the InGaN/diamond/Si substrate, and finally, introducing trimethyl aluminum and nitrogen gas into the reaction chamber to obtain the AlN/ZnO/InGaN/diamond/Si multilayer-structure surface acoustic wave filter. In the method, the diamond film is firstly deposited on the Si substrate, and the smooth high-crystallization-degree high-quality AlN nano piezoelectric film with high C-axis preferred orientation is deposited by using nano ZnO and InGaN films with high C-axis preferred orientation as buffer layers.