A method for sending control information, comprising: setting, by a network side device, respective control bits in a downlink control information, DCI, format to generate control information applied by the network side device to a terminal, wherein the control bits in the DCI format include a transmission block to codeword swap flag control bit, the transmission block to codeword swap flag control bit carrying indication information indicating whether to swap a corresponding relationship between a transmission block and a codeword, wherein when two codewords that are to be mapped to the transmission block are denoted CWO and CW1, respectively, and by default, a transmission block TB1 corresponds to CWO, and a transmission block TB2 corresponds to CW1, if the value of the transmission block to codeword swap flag control bit is 0, it indicates that the corresponding relationship between the transmission block and the codeword is not swapped, that is the TB1 corresponds to the CWO, and the TB2 corresponds to the CW1, and if the value of the transmission block to codeword swap flag control bit is 1, it indicates that the corresponding relationship between the transmission block and the codeword is swapped, that is the TB2 corresponds to the CWO, and the TB1 corresponds to the CW1; and if a dedicated demodulation reference signal used to demodulate data is preconfigured by the network side device for the terminal and respective codewords correspond to the same number of layers, said transmission block to codeword swap flag control bit includes control information other than an indication information indicating whether to swap a corresponding relationship between a transmission block and a codeword, and sending, by the network side device, the generated control information to the terminal. setting, by a network side device, respective control bits in a downlink control information, DCI, format to generate control information applied by the network side device to a terminal, wherein the control bits in the DCI format include a transmission block to codeword swap flag control bit, the transmission block to codeword swap flag control bit carrying indication information indicating whether to swap a corresponding relationship between a transmission block and a codeword, wherein when two codewords that are to be mapped to the transmission block are denoted CWO and CW1, respectively, and by default, a transmission block TB1 corresponds to CWO, and a transmission block TB2 corresponds to CW1, if the value of the transmission block to codeword swap flag control bit is 0, it indicates that the corresponding relationship between the transmission block and the codeword is not swapped, that is the TB1 corresponds to the CWO, and the TB2 corresponds to the CW1, and if the value of the transmission block to codeword swap flag control bit is 1, it indicates that the corresponding relationship between the transmission block and the codeword is swapped, that is the TB2 corresponds to the CWO, and the TB1 corresponds to the CW1; and if a dedicated demodulation reference signal used to demodulate data is preconfigured by the network side device for the terminal and respective codewords correspond to the same number of layers, said transmission block to codeword swap flag control bit includes control information other than an indication information indicating whether to swap a corresponding relationship between a transmission block and a codeword, and sending, by the network side device, the generated control information to the terminal.