A communication method, comprising: determining, by a terminal device, whether a power lower than a target transmission power of a first channel or signal is allowed to be used to transmit the first channel or signal during a first period within a time unit when a transmission power available to transmit the first channel or signal during the first period is lower than the target transmission power, wherein the transmission power available to transmit the first channel or signal during the first period is different from a power available to transmit the first channel or signal during at least one of other periods within the time unit; determining, by the terminal device, a current transmit power to be used to transmit the first channel or signal during the first period based on the transmission power available to transmit the first channel or signal during the first period when it is determined that the power lower than the target transmission power is allowed to be used to transmit the first channel or signal during the first period; transmitting, by the terminal device, the first channel or signal during the first period with the current transmit power; characterized in that determining, by a terminal device, whether a power lower than a target transmission power of a first channel or signal is allowed to be used to transmit the first channel or signal during a first period comprises at least one of the following: determining, by the terminal device, whether the power lower than the target transmission power is allowed to be used to transmit the first channel or signal during the first period based on a modulation mode and/or a modulation coding level of the first channel or signal; or determining, by the terminal device, whether the power lower than the target transmission power is allowed to be used to transmit the first channel or signal during the first period based on whether a reference signal for the first channel or signal is transmitted during the first period; or determining, by the terminal device, whether the power lower than the target transmission power is allowed to be used to transmit the first channel or signal during the first period based on indication information from a network device. determining, by a terminal device, whether a power lower than a target transmission power of a first channel or signal is allowed to be used to transmit the first channel or signal during a first period within a time unit when a transmission power available to transmit the first channel or signal during the first period is lower than the target transmission power, wherein the transmission power available to transmit the first channel or signal during the first period is different from a power available to transmit the first channel or signal during at least one of other periods within the time unit; determining, by the terminal device, a current transmit power to be used to transmit the first channel or signal during the first period based on the transmission power available to transmit the first channel or signal during the first period when it is determined that the power lower than the target transmission power is allowed to be used to transmit the first channel or signal during the first period; transmitting, by the terminal device, the first channel or signal during the first period with the current transmit power; characterized in that determining, by a terminal device, whether a power lower than a target transmission power of a first channel or signal is allowed to be used to transmit the first channel or signal during a first period comprises at least one of the following: determining, by the terminal device, whether the power lower than the target transmission power is allowed to be used to transmit the first channel or signal during the first period based on a modulation mode and/or a modulation coding level of the first channel or signal; or determining, by the terminal device, whether the power lower than the target transmission power is allowed to be used to transmit the first channel or signal during the first period based on whether a reference signal for the first channel or signal is transmitted during the first period; or determining, by the terminal device, whether the power lower than the target transmission power is allowed to be used to transmit the first channel or signal during the first period based on indication information from a network device.