A method, a system, and a terminal for sending and receiving a multicast broadcast service (MBS) are provided in the communication field. Based on a preset correspondence between MBS content IDs and LCIDs, a network side sends MBS data with an LCID corresponding to the MBS content ID in an air interface link identified by an MCID. A terminal generates a corresponding LCID from the MBS content ID of the MBS based on the same correspondence as that of the network side, and receives data via a logical channel identified by the LCID in the air interface link identified by the MCID of the required MBS. A method for assigning an MBS information ID is also provided. The uniqueness of the MBS content ID can be guaranteed within an operator, an access service network (ASN), or an MBS zone.