A method for transmitting uplink control information in a Long Term Evolution, LTE, or Fifth Generation, 5G, communication system, comprising: receiving, by a terminal device (102, 103, 700), downlink control information, wherein the downlink control information comprises resource information of a data channel, first indication information, and second indication information, the first indication information indicates a power offset value between a transmission time interval k and a transmission time interval k-1, and the second indication information is used to determine a power adjustment value in the transmission time interval k; determining (S420, S504, S604, S704), by the terminal device (102, 103, 700), transmit power in the transmission time interval k based on the power offset value and the power adjustment value; and transmitting (S430, S505, S605, S705), by the terminal device (102, 103, 700), uplink control information in the transmission time interval k based on the transmit power, wherein the uplink control information comprises feedback information for the data channel, and when the feedback information is a negative acknowledgment NACK, the transmit power is determined based on the power offset value and the power adjustment value, or when the feedback information is an acknowledgment ACK, the transmit power is determined based on the power offset value; wherein the second indication information is indication information of a reliability requirement, a remaining retransmission quantity, or a first combination of a reliability requirement and a remaining retransmission quantity; and before the determining (S420, S604, S704), by the terminal device (102, 103, 700), transmit power in the transmission time interval k based on the power offset value and the power adjustment value, the method further comprises: determining (S603, S703), by the terminal device (102, 103, 700), the power adjustment value based on the second indication information. receiving, by a terminal device (102, 103, 700), downlink control information, wherein the downlink control information comprises resource information of a data channel, first indication information, and second indication information, the first indication information indicates a power offset value between a transmission time interval k and a transmission time interval k-1, and the second indication information is used to determine a power adjustment value in the transmission time interval k; determining (S420, S504, S604, S704), by the terminal device (102, 103, 700), transmit power in the transmission time interval k based on the power offset value and the power adjustment value; and transmitting (S430, S505, S605, S705), by the terminal device (102, 103, 700), uplink control information in the transmission time interval k based on the transmit power, wherein the uplink control information comprises feedback information for the data channel, and when the feedback information is a negative acknowledgment NACK, the transmit power is determined based on the power offset value and the power adjustment value, or when the feedback information is an acknowledgment ACK, the transmit power is determined based on the power offset value; wherein the second indication information is indication information of a reliability requirement, a remaining retransmission quantity, or a first combination of a reliability requirement and a remaining retransmission quantity; and before the determining (S420, S604, S704), by the terminal device (102, 103, 700), transmit power in the transmission time interval k based on the power offset value and the power adjustment value, the method further comprises: determining (S603, S703), by the terminal device (102, 103, 700), the power adjustment value based on the second indication information.