The invention discloses a PCB manufacturing method, comprising the following steps: S10. Providing an inner-layer core plate to be holed and forming avoidance holes in the inner-layer core plate to be holed; S20, making adhesive blocking projections on the end faces of the inner-layer core plate to be holed and at the edges of the avoidance holes; S30, providing an hole-less core plate and a prepreg and laminating the hole-less core plate, the prepreg and the inner-layer core plate to be holed to form a laminated plate having a closed cavity. According to the scheme provided by the invention, since the adhesive blocking projections are formed at the edges of the avoidance holes, adhesive flowing inside the closed cavity can be controlled effectively and the complete shape of the inner wall can be ensured; moreover, the application of high-frequency high-speed material to the PCB having a closed cavity can be expanded and the signal transmission quality and speed can be enhanced.