An information sending method, comprising: sending, by a terminal device, a first message, MSG1, in a random access procedure, to a network device; generating (S31, S41), by the terminal device (800, 1000, 1200), a downlink channel quality report volume, wherein - the downlink channel quality report volume is used to indicate a relative relationship between a first number of repetitions and a second number of repetitions, - the first number of repetitions is a quantity of retransmissions that need to be performed in a first downlink control channel format to achieve a preset block error rate, - the second number of repetitions is a number of repetitions for common search space of a downlink control channel carried on a downlink carrier, and - the downlink carrier is a carrier for receiving a second message, MSG2, in a random access procedure; and sending (S32, S42, S72), by the terminal device (800, 1000, 1200), to the network device (900, 1100, 1300), a third message, MSG3, in the random access procedure, wherein the MSG3 is used to indicate the downlink channel quality report volume, wherein before a first message, MSG1, in the random access procedure is sent, performing, by the terminal device (800, 1000, 1200), measurement on a downlink anchor carrier, to obtain the first number of repetitions, or after a first MSG1 in the random access procedure is sent, performing, by the terminal device (800, 1000, 1200), measurement on the downlink carrier for receiving the MSG2 in the random access procedure, to obtain the first number of repetitions. sending, by a terminal device, a first message, MSG1, in a random access procedure, to a network device; generating (S31, S41), by the terminal device (800, 1000, 1200), a downlink channel quality report volume, wherein - the downlink channel quality report volume is used to indicate a relative relationship between a first number of repetitions and a second number of repetitions, - the first number of repetitions is a quantity of retransmissions that need to be performed in a first downlink control channel format to achieve a preset block error rate, - the second number of repetitions is a number of repetitions for common search space of a downlink control channel carried on a downlink carrier, and - the downlink carrier is a carrier for receiving a second message, MSG2, in a random access procedure; and - the downlink channel quality report volume is used to indicate a relative relationship between a first number of repetitions and a second number of repetitions, - the first number of repetitions is a quantity of retransmissions that need to be performed in a first downlink control channel format to achieve a preset block error rate, - the second number of repetitions is a number of repetitions for common search space of a downlink control channel carried on a downlink carrier, and - the downlink carrier is a carrier for receiving a second message, MSG2, in a random access procedure; and sending (S32, S42, S72), by the terminal device (800, 1000, 1200), to the network device (900, 1100, 1300), a third message, MSG3, in the random access procedure, wherein the MSG3 is used to indicate the downlink channel quality report volume, wherein before a first message, MSG1, in the random access procedure is sent, performing, by the terminal device (800, 1000, 1200), measurement on a downlink anchor carrier, to obtain the first number of repetitions, or after a first MSG1 in the random access procedure is sent, performing, by the terminal device (800, 1000, 1200), measurement on the downlink carrier for receiving the MSG2 in the random access procedure, to obtain the first number of repetitions.