1. A sub-frequency band sharing method, comprising:assigning a unique terminal sequence code to a user terminal, and sending the terminal sequence code to the user terminal when the user terminal is connected to a base station;
receiving a user data packet sent by a core network;
parsing the user data packet to acquire a destination user terminal to which the user data packet is to be sent;
acquiring a terminal sequence code corresponding to the destination user terminal;
acquiring an idle sub-frequency band in a frequency band, wherein the frequency band is divided into a plurality of sub-frequency bands, and one or a plurality of base stations connected to the user terminal and a plurality of user terminals serviced by the one or a plurality of base stations share the sub-frequency band to transmit data; and
modulating the user data packet and the acquired terminal sequence code to the idle sub-frequency band according to a predetermined sequence to form modulated data, wherein the modulated data is transmitted over the idle sub-frequency band, and upon completion of the transmission of the modulated data, the sub-frequency band occupied by the modulated data is released.