A channel detection method and system of an LTE system in an unlicensed frequency range, a device having base station functions, and a terminal are provided. The method includes: dividing an unlicensed frequency range into several frequency bands; setting a determination threshold value corresponding to each frequency band for detecting busy/idle states of channels in each frequency band; setting channel monitoring subframes for detecting the downlink channel state and/or the uplink channel state in each frequency band in the frame structure of the LTE system; detecting the busy/idle states of the downlink channel and/or the uplink channel in each frequency band according to the determination threshold value. The present invention increases a spectrum utilization rate of the unlicensed frequency range, and prevents an LTE system working in the unlicensed frequency range from causing large interference to other systems while ensuring the LTE system works in the unlicensed frequency range normally.