The invention discloses a printed circuit board (PCB) plating line. The PCB plating line comprises a PCB copper plating/ etching controller (1), a rack (2), a copper plating bath (4), a first rising baths (5) and a second rising baths (8), and a nitric acid bath (6), wherein a chuck (3) on the rack (2) clamps a PCB; and the PCB copper plating/ etching controller (1) controls a crown block to drive the rack (2) to run. The plating line is characterized in that: a dropping trough (7) is formed behind the nitric acid bath (6) and before the second rising bath (8) and is used for collecting a liquid medicament from the nitric acid bath (6); and a corresponding control program is arranged in the PCB copper plating/ etching controller (1) for controlling the dropping time of the rack (2) on the dropping trough (7). The improved printed circuit board (PCB) plating line has a simple structure; and the dropping trough is formed in the PCB plating line for collecting the liquid medicament from the nitric acid bath, so the amount of the liquid medicament flowing into the subsequent rising bath is reduced, water resources are saved, the treatment amount of waste water is reduced, the production cost is lowered, energy is saved and emission is reduced.