Embodiments of this application disclose a carrier configuration method and a related apparatus, so that a terminal device can fully use a spectrum resource when the spectrum resource is greater than a maximum carrier bandwidth at a subcarrier spacing. Specifically, the method includes: A radio access network device obtains an available spectrum resource bandwidth and a maximum carrier bandwidth at a subcarrier spacing. If the available spectrum resource bandwidth is greater than the maximum carrier bandwidth, the radio access network device configures a first carrier and a second carrier, where a sum of a first carrier bandwidth of the first carrier and a second carrier bandwidth of the second carrier is greater than the available spectrum resource bandwidth, and the sum of the first carrier bandwidth and the second carrier bandwidth minus an overlapping bandwidth between the first carrier and the second carrier equals the available spectrum resource bandwidth.