Embodiments of this application disclose a random access method. The method includes: obtaining, by a first network device, resource information corresponding to a target service unit, where the resource information is used to indicate a resource to be used, by a user equipment (UE) that has established a connection to the first network device, to send a physical random access channel (PRACH) via the target service unit, and the target service unit is a cell to be accessed by the UE or at least one beam to be accessed by the UE; and sending, by the first network device, a notification message to the UE, where the notification message includes the resource information.