A communications method, comprising: receiving, by a transmit terminal, configuration information from a network device, wherein the configuration information comprises resource pool information of a sidelink of the transmit terminal, the resource pool information comprises information about one or more resource pools, and information about one resource pool comprises one or more of information about a physical sidelink feedback channel, PSFCH, frequency domain resource; sending, by the transmit terminal, multicast data to receive terminals in a multicast group; and receiving, by the transmit terminal, feedback information of the multicast data from the receive terminals in the multicast group on the PSFCH frequency domain resource, wherein the method further comprising: determining, by the transmit terminal, a resource pool based on the resource pool information and a quantity of receive terminals in the multicast group; and determining, by the transmit terminal, a frequency domain resource used to send the multicast data, in the resource pool, wherein when the frequency domain resource comprises one subchannel, the subchannel meets the following condition: a maximum sequence interval calculated based on the quantity of receive terminals in the multicast group and a PSFCH frequency domain resource on the subchannel is greater than or equal to a sequence interval of sequences on a PSFCH on the subchannel. receiving, by a transmit terminal, configuration information from a network device, wherein the configuration information comprises resource pool information of a sidelink of the transmit terminal, the resource pool information comprises information about one or more resource pools, and information about one resource pool comprises one or more of information about a physical sidelink feedback channel, PSFCH, frequency domain resource; sending, by the transmit terminal, multicast data to receive terminals in a multicast group; and receiving, by the transmit terminal, feedback information of the multicast data from the receive terminals in the multicast group on the PSFCH frequency domain resource, wherein the method further comprising: determining, by the transmit terminal, a resource pool based on the resource pool information and a quantity of receive terminals in the multicast group; and determining, by the transmit terminal, a frequency domain resource used to send the multicast data, in the resource pool, wherein when the frequency domain resource comprises one subchannel, the subchannel meets the following condition: a maximum sequence interval calculated based on the quantity of receive terminals in the multicast group and a PSFCH frequency domain resource on the subchannel is greater than or equal to a sequence interval of sequences on a PSFCH on the subchannel. determining, by the transmit terminal, a resource pool based on the resource pool information and a quantity of receive terminals in the multicast group; and determining, by the transmit terminal, a frequency domain resource used to send the multicast data, in the resource pool, wherein when the frequency domain resource comprises one subchannel, the subchannel meets the following condition: a maximum sequence interval calculated based on the quantity of receive terminals in the multicast group and a PSFCH frequency domain resource on the subchannel is greater than or equal to a sequence interval of sequences on a PSFCH on the subchannel.