The present disclosure relates to the technical field of communications, and provides a clear channel listening method and apparatus and a device. The method comprises: determining a signal block set, the signal block set comprising n signal blocks; each signal block comprising at least one signal and/or at least one channel; n being an integer greater than 1; executing one clear channel assessment (CCA) on a channel of an unlicensed spectrum before transmitting the signal blocks comprised in the signal block set; and if the CCA result is that the channel of the unlicensed spectrum is available, using the channel of the unlicensed spectrum to transmit the signal blocks comprised in the signal block set. The present disclosure provides a solution for using an unlicensed spectrum to transmit signal blocks in an NR system, which may meet the CCA detection time by the intervals among the signal blocks.