A method for feeding back sidelink transmission, comprising: obtaining, by a terminal device, an uplink feedback resource, wherein the terminal device uses the uplink feedback resource to transmit feedback information of a sidelink to a network device; and performing, by the terminal device, sidelink feedback processing, characterized in that the performing, by the terminal device, the sidelink feedback processing comprises: performing, by the terminal device, initial transmission and retransmission of a transmission block by using multiple sidelink resources; receiving, by the terminal device, multiple feedback information corresponding to the transmission block; sending, by the terminal device, target feedback information among the multiple feedback information, to the network device on the uplink feedback resource, the target feedback information being used to indicate reception of sidelink data carried by a target resource in the multiple sidelink resources, wherein the resource with the latest time-domain position among the multiple sidelink resources is the target resource, or the terminal device determines the resource corresponding to the ACK received for the first time among the multiple feedback information as the target resource. obtaining, by a terminal device, an uplink feedback resource, wherein the terminal device uses the uplink feedback resource to transmit feedback information of a sidelink to a network device; and performing, by the terminal device, sidelink feedback processing, characterized in that the performing, by the terminal device, the sidelink feedback processing comprises: performing, by the terminal device, initial transmission and retransmission of a transmission block by using multiple sidelink resources; receiving, by the terminal device, multiple feedback information corresponding to the transmission block; sending, by the terminal device, target feedback information among the multiple feedback information, to the network device on the uplink feedback resource, the target feedback information being used to indicate reception of sidelink data carried by a target resource in the multiple sidelink resources, wherein the resource with the latest time-domain position among the multiple sidelink resources is the target resource, or the terminal device determines the resource corresponding to the ACK received for the first time among the multiple feedback information as the target resource. performing, by the terminal device, initial transmission and retransmission of a transmission block by using multiple sidelink resources; receiving, by the terminal device, multiple feedback information corresponding to the transmission block; sending, by the terminal device, target feedback information among the multiple feedback information, to the network device on the uplink feedback resource, the target feedback information being used to indicate reception of sidelink data carried by a target resource in the multiple sidelink resources, wherein the resource with the latest time-domain position among the multiple sidelink resources is the target resource, or the terminal device determines the resource corresponding to the ACK received for the first time among the multiple feedback information as the target resource.