Embodiments provide a method for sending a signal by user equipment and user equipment. The method includes: within an obtained channel detection cycle, detecting a first interference strength within system bandwidth and a second interference strength on each sub-band within the system bandwidth; comparing the first interference strength with a first interference threshold; if the first interference strength is less than the first interference threshold, selecting, from the system bandwidth according to the second interference strength on each sub-band within the system bandwidth, N first sub-bands that receive relatively small interference; and sending a signal on the N first sub-bands. In consideration of interference within the entire bandwidth and interference to each sub-band, when interference to the entire system is relatively small, a transmission collision is avoided. In addition, selecting sub-bands that receive small interference for signal transmission further reduces transmission interference, thereby effectively improving data transmission reliability.