A feedback information sending method, comprising: receiving, by a second device, a first transport block, TB, from a first device, wherein the first TB comprises a plurality of code block groups, CBGs, the plurality of CBGs comprise one or more first CBG and one or more second CBG that are received by the second device in a first time unit, the one or more first CBG received in the first time unit is successfully decoded, and the one or more second CBG received in the first time unit is unsuccessfully decoded; receiving, by the second device in a second time unit after the first time unit, a retransmission of only the one or more second CBG; generating, by the second device, a first feedback information set, wherein the first feedback information set comprises first feedback information and second feedback information, the first feedback information is used to feed back a decoding status of the one or more first CBG between the first time unit and a second time unit, and the first feedback information is used to feed back a decoding status of the one or more first CBG received in the first time unit, the second feedback information is used to feed back a decoding status of the one or more second CBG received in the second time unit; and sending, by the second device, the first feedback information set to the first device in a third time unit, characterised in that when the one or more second CBG is unsuccessfully decoded between the second time unit and the third time unit, the first feedback information includes at least one ACK, wherein the at least one ACK has a one-to-one correspondence with the one or more first CBG; when the one or more second CBG is successfully decoded between the second time unit and the third time unit and the first TB is successfully checked between the second time unit and the third time unit, the first feedback information includes at least one ACK, wherein the at least one ACK has a one-to-one correspondence with the one or more first CBG; and when the one or more second CBG is successfully decoded between the second time unit and the third time unit, and the first TB is unsuccessfully checked between the second time unit and the third time unit, the first feedback information includes at least one NACK, wherein the at least one NACK has a one-to-one correspondence with the one or more first CBG. receiving, by a second device, a first transport block, TB, from a first device, wherein the first TB comprises a plurality of code block groups, CBGs, the plurality of CBGs comprise one or more first CBG and one or more second CBG that are received by the second device in a first time unit, the one or more first CBG received in the first time unit is successfully decoded, and the one or more second CBG received in the first time unit is unsuccessfully decoded; receiving, by the second device in a second time unit after the first time unit, a retransmission of only the one or more second CBG; generating, by the second device, a first feedback information set, wherein the first feedback information set comprises first feedback information and second feedback information, the first feedback information is used to feed back a decoding status of the one or more first CBG between the first time unit and a second time unit, and the first feedback information is used to feed back a decoding status of the one or more first CBG received in the first time unit, the second feedback information is used to feed back a decoding status of the one or more second CBG received in the second time unit; and sending, by the second device, the first feedback information set to the first device in a third time unit, characterised in that when the one or more second CBG is unsuccessfully decoded between the second time unit and the third time unit, the first feedback information includes at least one ACK, wherein the at least one ACK has a one-to-one correspondence with the one or more first CBG; when the one or more second CBG is successfully decoded between the second time unit and the third time unit and the first TB is successfully checked between the second time unit and the third time unit, the first feedback information includes at least one ACK, wherein the at least one ACK has a one-to-one correspondence with the one or more first CBG; and when the one or more second CBG is successfully decoded between the second time unit and the third time unit, and the first TB is unsuccessfully checked between the second time unit and the third time unit, the first feedback information includes at least one NACK, wherein the at least one NACK has a one-to-one correspondence with the one or more first CBG.