A method for transmitting a physical downlink control channel, comprising: determining, by a first communication node, an actual transmitting mode set based on a candidate transmitting mode set, wherein the candidate transmitting mode set comprises X transmitting modes, X is an integer greater than or equal to 1, the actual transmitting mode set comprises Y transmitting modes, and Y is an integer greater than or equal to 1 and not greater than X; and transmitting, by the first communication node, a physical downlink control channel to a second communication node according to the actual transmitting mode set; wherein before determining, by the first communication node, the actual transmitting mode set based on the candidate transmitting mode set, the method further comprises: determining, by the first communication node, the candidate transmitting mode set according to information related to a first feedback information, wherein the first feedback information is feedback information related to at least a candidate transmitting mode, which is transmitted from the second communication node; characterized in that the method further comprises: executing, by the first communication node, the step of transmitting the physical downlink control channel to the second communication node according to the actual transmitting mode set after the first communication node receives the first feedback information and waits for at least Z time intervals, wherein a value of Z is configured by default or is acknowledged by negotiating of the first communication node and the second communication node. determining, by a first communication node, an actual transmitting mode set based on a candidate transmitting mode set, wherein the candidate transmitting mode set comprises X transmitting modes, X is an integer greater than or equal to 1, the actual transmitting mode set comprises Y transmitting modes, and Y is an integer greater than or equal to 1 and not greater than X; and transmitting, by the first communication node, a physical downlink control channel to a second communication node according to the actual transmitting mode set; wherein before determining, by the first communication node, the actual transmitting mode set based on the candidate transmitting mode set, the method further comprises: determining, by the first communication node, the candidate transmitting mode set according to information related to a first feedback information, wherein the first feedback information is feedback information related to at least a candidate transmitting mode, which is transmitted from the second communication node; characterized in that the method further comprises: executing, by the first communication node, the step of transmitting the physical downlink control channel to the second communication node according to the actual transmitting mode set after the first communication node receives the first feedback information and waits for at least Z time intervals, wherein a value of Z is configured by default or is acknowledged by negotiating of the first communication node and the second communication node. determining, by the first communication node, the candidate transmitting mode set according to information related to a first feedback information, wherein the first feedback information is feedback information related to at least a candidate transmitting mode, which is transmitted from the second communication node; characterized in that the method further comprises: executing, by the first communication node, the step of transmitting the physical downlink control channel to the second communication node according to the actual transmitting mode set after the first communication node receives the first feedback information and waits for at least Z time intervals, wherein a value of Z is configured by default or is acknowledged by negotiating of the first communication node and the second communication node.