The invention provides a method for sending and detecting downlink control information, a base station carries the downlink control information in a physical downlink control signal channel, the physical downlink control signal channel is sent through a component carrier, wherein the base station carries the first type of downlink control information on the main component carrier and carries the third type of downlink control information on the first component carrier, the first type of downlink control information carries uplink and / or downlink scheduling information and / or uplink power control information of the component carrier in which the first type of downlink control information is located, the second type of downlink control information carries uplink and / or downlink scheduling information of one or a plurality of component carriers, and the third type of downlink control information carries indication information of the second type of downlink control information. A terminal detects the first type of downlink control information on the main component carrier and detects the third type of downlink control information on the first component carrier. The method has better scheduling flexibility, compatibility and error code performance, lower blind detection times and lower signaling cost.