This application discloses a signal transmission method. The method may include: receiving, by a first device, reference configuration information for a signal resource sent by a second device, where the reference signal is used to measure interference between a first link and a second link, the first link is a link between the first device and a fourth device, the second link is a link between the second device and a third device, and the first device and the second device are relay nodes between the third device and the fourth device; and sending or receiving, by the first device, a reference signal on a reference signal resource indicated by the resource configuration information for the signal resource.