A feedback information transmission method, comprising: receiving, by a terminal device, at least one physical downlink shared channel, PDSCH, in at least one first time unit in a time unit set, wherein the at least one first time unit corresponding to at least one frequency domain unit configured for the terminal device, wherein the first time unit is a downlink slot; determining, by the terminal device, a second time unit, wherein the second time unit is used to carry feedback information corresponding to the at least one PDSCH, and there is a first association relationship between the time unit set and the second time unit, wherein the second time unit is an uplink slot; determining, by the terminal device, a first codebook, wherein when the at least one PDSCH in a time unit subset meets a preset condition, the first codebook comprises feedback information corresponding to the at least one PDSCH, the first codebook does not comprise feedback information corresponding to another first time unit in the time unit set other than a first time unit in which the at least one PDSCH is located, the preset condition comprises a first condition, the first condition is that the number of the at least one PDSCH is equal to 1, the time unit subset is a subset of the time unit set, and there is a second association relationship between the time unit subset and the second time unit; and sending, by the terminal device, uplink control information in the second time unit, wherein the uplink control information carries the first codebook, wherein the first association relationship is predefined according to a standard or configured for the terminal device by a network device via radio resource control, RRC, signaling, and the second association relationship is indicated by timing indication information carried on a downlink control channel for dynamically scheduling the at least one PDSCH. receiving, by a terminal device, at least one physical downlink shared channel, PDSCH, in at least one first time unit in a time unit set, wherein the at least one first time unit corresponding to at least one frequency domain unit configured for the terminal device, wherein the first time unit is a downlink slot; determining, by the terminal device, a second time unit, wherein the second time unit is used to carry feedback information corresponding to the at least one PDSCH, and there is a first association relationship between the time unit set and the second time unit, wherein the second time unit is an uplink slot; determining, by the terminal device, a first codebook, wherein when the at least one PDSCH in a time unit subset meets a preset condition, the first codebook comprises feedback information corresponding to the at least one PDSCH, the first codebook does not comprise feedback information corresponding to another first time unit in the time unit set other than a first time unit in which the at least one PDSCH is located, the preset condition comprises a first condition, the first condition is that the number of the at least one PDSCH is equal to 1, the time unit subset is a subset of the time unit set, and there is a second association relationship between the time unit subset and the second time unit; and sending, by the terminal device, uplink control information in the second time unit, wherein the uplink control information carries the first codebook, wherein the first association relationship is predefined according to a standard or configured for the terminal device by a network device via radio resource control, RRC, signaling, and the second association relationship is indicated by timing indication information carried on a downlink control channel for dynamically scheduling the at least one PDSCH.