A base station access system and a base station data transmission method. The system includes a base station and a broadband access point. An embodiment of base station data transmission method includes: a base station assigns sequence number identifications to uplink data packets, the base station sends the uplink data packets with the sequence number identifications out via multiple xDSL links; by the broadband access point arranges the uplink data packets according to the sequence number identifications of the received uplink data packets, broadband access point extracts the arranged uplink data packets, the broadband access point sends the extracted uplink data packets out. The embodiment of the present invention improves the transmission band of the base station accessing while ensuring the transmission distance of the base station accessing.