A method for detecting a Physical Downlink Control Channel, PDCCH, comprising: a User Equipment, UE, detecting a downlink control channel of the UE in a first search space and a second search space, wherein the first search space and the second search space are resources for a base station to send downlink control channel information, wherein said downlink control channel is the Physical Downlink Control Channel Physical Downlink Control Channel, PDCCH; wherein the first search space is distributed in a subframe or a time slot or a time-frequency location; and the second search space is distributed in another subframe or another time slot or another time-frequency location, wherein time-frequency at which the first search space is located and time-frequency at which the second search space is located can overlap; characterized in that the step of the UE detecting the downlink control channel in the first search space and/or the second search space comprises: the UE using a configuration of {a, b, c, d} as the number of the downlink control channel candidates to detect the downlink control channel, wherein a, b, c and d are all positive integers and a + b + c + d is less than or equals 8, wherein a is the number of PDCCH candidates to be detected in the first search space and/or the second search space for aggregation level L=1, b is the number of PDCCH candidates to be detected in the first search space and/or the second search space for aggregation level L=2, c is the number of PDCCH candidates to be detected in the first search space and/or the second search space for aggregation level L=4, d is the number of PDCCH candidates to be detected in the first search space and/or the second search space for aggregation level L=8. a User Equipment, UE, detecting a downlink control channel of the UE in a first search space and a second search space, wherein the first search space and the second search space are resources for a base station to send downlink control channel information, wherein said downlink control channel is the Physical Downlink Control Channel Physical Downlink Control Channel, PDCCH; wherein the first search space is distributed in a subframe or a time slot or a time-frequency location; and the second search space is distributed in another subframe or another time slot or another time-frequency location, wherein time-frequency at which the first search space is located and time-frequency at which the second search space is located can overlap; characterized in that the step of the UE detecting the downlink control channel in the first search space and/or the second search space comprises: the UE using a configuration of {a, b, c, d} as the number of the downlink control channel candidates to detect the downlink control channel, wherein a, b, c and d are all positive integers and a + b + c + d is less than or equals 8, wherein a is the number of PDCCH candidates to be detected in the first search space and/or the second search space for aggregation level L=1, b is the number of PDCCH candidates to be detected in the first search space and/or the second search space for aggregation level L=2, c is the number of PDCCH candidates to be detected in the first search space and/or the second search space for aggregation level L=4, d is the number of PDCCH candidates to be detected in the first search space and/or the second search space for aggregation level L=8.