In one aspect of the disclosure, a channel detection method applied when an LTE system works in an unlicensed frequency band comprises determining a current sub-frame and a channel detection time when a data traffic arrives, wherein the channel detection time is set in at least one of the current sub-frame and a next adjacent sub-frame to perform channel state detection, and judging whether the terminal or base station that performs the channel state detection and other terminals or base stations belong to a same telecommunication operator in order to perform the channel state detection in a corresponding way; and performing data traffic transmission when it is detected that the channel is in an idle state. Other aspects of the disclosure relates to a terminal and a base station using the channel detection method.