The present invention relates to the field of communications technologies and discloses a multi-site cell communication method, a base station controller, a base station, and a communication system thereof to increase cell capacity of a base station based on a multi-site cell technology. A multi-site cell communication method includes: when the terminals that respectively access different subsites occupy different logical channels, handing over terminals, which access different subsites respectively, to a same logical channel. A multi-site cell communication method includes: using a same logical channel to modulate and send downlink data to terminals that access different subsites respectively; and/or receiving and demodulating uplink data that is sent through the same logical channel by the terminals that access different subsites respectively.