The present invention discloses a superposition coding method, apparatus, and system, The method of the present invention includes: generating a superposition coding signal according to bit data to be separately sent to the at least two user equipments (UEs); sending notification signaling to at least one UE in the at least two UEs, where the notification signaling carries data selection information, and the data selection information is used for instructing the UE to acquire, from bit data demodulated from the superposition coding signal, at least one bit of data that is of a specific quantity and at a specific location as received data; and sending the superposition coding signal to the at least two UEs. The present invention is mainly applied in a demodulation process of a superposition coding signal.