This application discloses a satellite network communication method and a related apparatus, and relates the field of communications technologies. The method includes: determining user device address information of a user device, where the user device address information includes a second sub-area identifier EID and a user device identifier UDID of the user device, the second EID is used to indicate a second sub-area in which the user device is currently located, and the second sub-area is one of a plurality of sub-areas divided from the earth surface; and sending, by the user device, the user device address information to a first satellite. The identifier of the sub-area in which the user device is located is included in the user device address information. This can adapt to a high-speed mobility feature of a satellite on a satellite network and improve communication efficiency of the satellite network.