A method for sending uplink control information, wherein a user terminal sends hybrid automatic repeat request-acknowledgment, HARQ-ACK, information and periodic channel state information, CSI, of at least one of multiple downlink carriers, by using a channel resource, and the method comprises: receiving, by the user terminal by using the at least one of the multiple downlink carriers, downlink data transmitted by a network device; obtaining, by the user terminal from the network device, a code rate information of the HARQ-ACK information; determining, by the user terminal according to a code rate of the HARQ-ACK information corresponding to the code rate information of the HARQ-ACK information, a bit quantity of periodic CSI that can be sent on the channel resource, wherein a code rate of the periodic CSI is the same as the code rate of the HARQ-ACK information and the code rate corresponds to a target received bit error rate of the HARQ-ACK and a channel condition; wherein the bit quantity of the periodic CSI that can be sent on the channel resource is less than or equal to a difference between a maximum bit quantity of uplink control information, UCI, that can be transmitted on the channel resource and an original bit quantity of the HARQ-ACK information, and the maximum bit quantity of the UCI that can be transmitted on the channel resource corresponds to the code rate and a total resource quantity of the channel resource; determining, by the user terminal according to the bit quantity of the periodic CSI that can be sent, to-be-sent periodic CSI from periodic CSI corresponding to the multiple downlink carriers; encoding, by the user terminal, the to-be-sent periodic CSI and the HARQ-ACK information according to the code rate; sending, by the user terminal, the encoded HARQ-ACK information and the encoded to-be-sent periodic CSI on the channel resource. receiving, by the user terminal by using the at least one of the multiple downlink carriers, downlink data transmitted by a network device; obtaining, by the user terminal from the network device, a code rate information of the HARQ-ACK information; determining, by the user terminal according to a code rate of the HARQ-ACK information corresponding to the code rate information of the HARQ-ACK information, a bit quantity of periodic CSI that can be sent on the channel resource, wherein a code rate of the periodic CSI is the same as the code rate of the HARQ-ACK information and the code rate corresponds to a target received bit error rate of the HARQ-ACK and a channel condition; wherein the bit quantity of the periodic CSI that can be sent on the channel resource is less than or equal to a difference between a maximum bit quantity of uplink control information, UCI, that can be transmitted on the channel resource and an original bit quantity of the HARQ-ACK information, and the maximum bit quantity of the UCI that can be transmitted on the channel resource corresponds to the code rate and a total resource quantity of the channel resource; the bit quantity of the periodic CSI that can be sent on the channel resource is less than or equal to a difference between a maximum bit quantity of uplink control information, UCI, that can be transmitted on the channel resource and an original bit quantity of the HARQ-ACK information, and the maximum bit quantity of the UCI that can be transmitted on the channel resource corresponds to the code rate and a total resource quantity of the channel resource; determining, by the user terminal according to the bit quantity of the periodic CSI that can be sent, to-be-sent periodic CSI from periodic CSI corresponding to the multiple downlink carriers; encoding, by the user terminal, the to-be-sent periodic CSI and the HARQ-ACK information according to the code rate; sending, by the user terminal, the encoded HARQ-ACK information and the encoded to-be-sent periodic CSI on the channel resource.