Preparation method of ceramic copper-clad substrate

The invention discloses a preparation method of a ceramic copper-clad substrate. The preparation method comprises the following steps: copper sheet selection, wherein the surface of a copper sheet should not be seriously oxidized, discolored or polluted, the purity of the copper sheet is 99%-99.99%, the hardness of the copper sheet is 90-110 HV, and the conductivity of the copper sheet is 58-60 MS/m; selection of a ceramic substrate, wherein the ceramic substrate is fine and white in appearance and does not have obvious defects, spots, cracks and ceramic fences; pretreatment, wherein ultrasonic cleaning is conducted on the surfaces of the selected copper sheet and the selected ceramic substrate to remove dust and oil stains on the surfaces, and then rapid air drying is conducted; treatment, wherein the pretreated copper sheet is put into air to be oxidized so as to allow a copper oxide transition layer to be formed on a junction surface, then the copper sheet is tidily laid on the ceramic substrate, sintering