Embodiments disclose a random access method, a device, and a system, and relate to the field of communications technologies, to resolve a problem of how to implement network access when two or more uplink frequency bands exist in a 5G system. A specific solution is as follows: A terminal receives, from an access network device, random access configurations corresponding to at least two uplink frequency bands, and initiates random access based on at least one of the random access configurations corresponding to the at least two uplink frequency bands. The embodiments are used for a random access process.