The invention discloses a manufacturing method of a step-type circuit board. The manufacturing method comprises the following steps: a first area where a circuit pattern needs to be formed in a step-slot range on an inner-layer board is electrically plated and thickened by at least 100 micrometers; an inner-layer line pattern is machined on the surface of the inner-layer board, wherein a first line pattern is formed in the first area in the step-slot range; an outer-layer board is arranged on an upper layer of the inner-layer board, and an outer-layer line pattern is machined in a surface of the outer-layer board; a step slot with the bottom reaching the first line pattern is machined in step-slot range of the outer-layer board in a depth milling control process. Due to the fact that gaskets do not need to be used in the technical scheme, the problems that the gaskets cannot be removed easily and are left can be avoided, and the problem that layering is likely to occur due to the gaskets can be also avoided; additionally, when multiple step slots need to the machined, all that is needed is to laminate the inner-layer board and the outer-layer board to reach a needed number of layers once and then machine the step slots in the outer-layer board in the depth milling control process, and the problem that layering is likely to occur due to multiple times of lamination can be avoided.