The present invention provides a method, base station, and user equipment for transmitting a control channel. Grouping is performed, according to an aggregation level of the to-be-transmitted control channel, on sub-blocks in physical resource blocks configured by the base station for the to-be-transmitted control channel, then interleaving is performed, and then candidate control channels are mapped to the interleaved sub-blocks, so that any candidate control channel of the to-be-transmitted control channel is sent on consecutive time-frequency resources as possible, and meanwhile different candidate control channels are on different PRB pairs as possible. In this way, the base station may have better flexibility during actual sending of the ePDCCH, thereby not only achieving a precoding gain and facilitating better transmission of control information, but also achieving a larger scheduling gain.