Preparation method of stepped circuit board and stepped circuit board

The invention discloses a preparation method of a stepped circuit board and the stepped circuit board, and the method comprises the steps: covering a first region of a first surface of a first circuit board with a first protection layer, forming a bonding pad in the first region, and covering the bonding pad with the first protection layer; a first bonding layer is formed on the first surface, and the first bonding layer covers the first circuit board and the first protection layer; a second circuit board is formed on the side, away from the first circuit board, of the first bonding layer, the second circuit board is bonded with the first circuit board through the first bonding layer, and the second circuit board covers the first bonding layer; cutting the second circuit board until the cutting depth reaches the surface, deviating from the first circuit board, of the first protection layer; and separating the first protection layer from the first circuit board so as to remove the second circuit board in the f