The invention discloses a manufacturing process of a high-fall stepped circuit board. The manufacturing process comprises the steppeds of: manufacturing inner-layer circuits on a plurality of core boards separately, and manufacturing an auxiliary copper skin at a position corresponding to a stepped platform when the inner-layer circuit is manufactured on one of the core board; laminating the plurality of core boards into a multi-layer board; performing intermediate processing on the multi-layer board sequentially; performing depth-control groove milling inwardly at a position corresponding tothe stepped platform on the multi-layer board to a position 0.1 mm +/- 0.075 mm away from the auxiliary copper skin beform outer layer etching during the manufacturing process of an outer layer circuit, and forming the stepped platform after removing a cover; performing ablation on a residual dielectric layer at the bottom part at the stepped platform by means of laser; manufacturing the outer layer circuit through etching and removing the auxiliary copper skin at the stepped platform at the same time; and performing post-procedure processing on the multi-layer board to manufacture the high-fall stepped circuit board. According to the manufacturing process, the core board thickness is adopted to make a residual thickness step, the residual thickness tolerance of the stepped platform aftermolding and milling is ensured to meet requirements, the high-precision residual thickness tolerance is ensured to be realized, and the production efficiency can be improved.