Method and apparatus are provided for mapping and detecting a control channel. For the same aggregation level, according to a signaling length of a control channel corresponding to a component carrier, a corresponding search space is determined for at least two control channels that have the same signaling length, so as to enable the at least two control channels that have the same signaling length to use the same search space. The at least two control channels having the same signaling length are mapped to the determined corresponding search space. Therefore, conflicts between the control channels are reduced, and the number of times of blind detection of the control channels is also reduced.