A multicast service transmission method, wherein the method is applied to a first network device, wherein a terminal is connected to the first network device and to a second network device, and wherein the network devices use a carrier aggregation, CA, technology to send a scrambled physical downlink control channel, PDCCH, scrambled using a radio network temporary identifier, RNTI, for scheduling the multicast service to the terminal device by using a part of a plurality of component carriers, CCs, corresponding to cells; and the method comprises: determining (401, 704) first configuration information, wherein the first configuration information is for indicating a terminal device to receive a first multicast service, and the first configuration information comprises a cell identifier of a serving cell corresponding to the first multicast service and one or more of the following information: an identifier of the first multicast service and the radio network temporary identifier, RNTI, corresponding to the first multicast service; and sending (402, 603, 705) the first configuration information to the terminal device, so that the terminal device receives, based on the configuration information related to the multicast service, the multicast service in the specified serving cell by monitoring the PDCCH only in the specified serving cell and using the corresponding RNTI; wherein the method further comprises: sending (601, 702) first information to a second network device, wherein the first information comprises an identifier of the terminal device and the identifier of the first multicast service, and the first information is for indicating that the terminal device needs to receive the first multicast service; receiving (602, 703) second configuration information from the second network device; and the determining (401, 704) of the first configuration information is based on the received second configuration information; wherein the second configuration information comprises the identifier of the first multicast service, the RNTI, and the cell identifier of the serving cell corresponding to the first multicast service. determining (401, 704) first configuration information, wherein the first configuration information is for indicating a terminal device to receive a first multicast service, and the first configuration information comprises a cell identifier of a serving cell corresponding to the first multicast service and one or more of the following information: an identifier of the first multicast service and the radio network temporary identifier, RNTI, corresponding to the first multicast service; and sending (402, 603, 705) the first configuration information to the terminal device, so that the terminal device receives, based on the configuration information related to the multicast service, the multicast service in the specified serving cell by monitoring the PDCCH only in the specified serving cell and using the corresponding RNTI; wherein the method further comprises: sending (601, 702) first information to a second network device, wherein the first information comprises an identifier of the terminal device and the identifier of the first multicast service, and the first information is for indicating that the terminal device needs to receive the first multicast service; receiving (602, 703) second configuration information from the second network device; and the determining (401, 704) of the first configuration information is based on the received second configuration information; wherein the second configuration information comprises the identifier of the first multicast service, the RNTI, and the cell identifier of the serving cell corresponding to the first multicast service. sending (601, 702) first information to a second network device, wherein the first information comprises an identifier of the terminal device and the identifier of the first multicast service, and the first information is for indicating that the terminal device needs to receive the first multicast service; receiving (602, 703) second configuration information from the second network device; and the determining (401, 704) of the first configuration information is based on the received second configuration information; wherein the second configuration information comprises the identifier of the first multicast service, the RNTI, and the cell identifier of the serving cell corresponding to the first multicast service.