A method for determining a Hybrid Automatic Repeat reQuest, HARQ, codebook, configured to operate in a New Radio, NR, system, comprising: receiving, by a terminal device from a network device, first Downlink Control Information, DCI, wherein the first DCI is used for scheduling a first Physical Downlink Shared Channel, PDSCH, the first PDSCH belongs to a first channel group in a plurality of channel groups, the first DCI comprises first indication information and valid HARQ timing indicator information, wherein the first indication information is used for indicating whether feeding back is triggered for a channel group except the first channel group in the plurality of channel groups; wherein the channel groups are PDSCH channel groups; determining, by the terminal device, first uplink resource based on the valid HARQ timing indicator information; determining, by the terminal device, a first HARQ codebook corresponding to the plurality of channel groups for the first uplink resource; and sending, by the terminal device, the first HARQ codebook to the network device; wherein the quantity of the plurality of channel groups is predefined; wherein Downlink assignment indexes, DAIs, that correspond to the PDSCHs in the plurality of channel groups are counted consecutively; wherein when a first DAI corresponding to the first PDSCH in the first channel group is not an initial value, information of a starting position of the first HARQ codebook is placeholder information; wherein the placeholder information is NACK information, or a position corresponding to the placeholder information is not used for placing the codebook; wherein the information of the first HARQ codebook between the starting position and a position corresponding to the first DAI is the placeholder information, wherein the position corresponding to the first DAI is a position, determined based on a count of the first DAI, in the first HARQ codebook. receiving, by a terminal device from a network device, first Downlink Control Information, DCI, wherein the first DCI is used for scheduling a first Physical Downlink Shared Channel, PDSCH, the first PDSCH belongs to a first channel group in a plurality of channel groups, the first DCI comprises first indication information and valid HARQ timing indicator information, wherein the first indication information is used for indicating whether feeding back is triggered for a channel group except the first channel group in the plurality of channel groups; wherein the channel groups are PDSCH channel groups; determining, by the terminal device, first uplink resource based on the valid HARQ timing indicator information; determining, by the terminal device, a first HARQ codebook corresponding to the plurality of channel groups for the first uplink resource; and sending, by the terminal device, the first HARQ codebook to the network device; wherein the quantity of the plurality of channel groups is predefined; wherein Downlink assignment indexes, DAIs, that correspond to the PDSCHs in the plurality of channel groups are counted consecutively; wherein when a first DAI corresponding to the first PDSCH in the first channel group is not an initial value, information of a starting position of the first HARQ codebook is placeholder information; wherein the placeholder information is NACK information, or a position corresponding to the placeholder information is not used for placing the codebook; wherein the information of the first HARQ codebook between the starting position and a position corresponding to the first DAI is the placeholder information, wherein the position corresponding to the first DAI is a position, determined based on a count of the first DAI, in the first HARQ codebook.