This application provides a multilayer printed circuit board (PCB). There is a pad array on a surface of the multilayer PCB. The pad array includes at least one padding unit, and each padding unit includes a first pad and a second pad that are adjacent. Both the first pad and the second pad are connected to a first Z-directed transmission line located in a Z-directed groove. In this way, to wire a signal wire on a signal layer of the multilayer PCB, a quantity of Z-directed grooves that need to be bypassed is less than a quantity of vias that need to be bypassed in the prior art. In other words, wiring of the signal wire is easier to some extent. In addition, this application further provides a corresponding communications device.