Examples in this application disclose satellite network communication methods, communications apparatuses, and communications systems. One example method includes determining, by a user device, address information of the user device, where the address information includes a second sub-area identifier and a user device identifier (UDID) of the user device, and the second EID indicates a second sub-area which the user device is currently located in, and the second sub-area is one of a plurality of sub-areas divided from earth surface, and sending, by the user device, the address information to a first satellite.