A method for transmitting a control channel, comprising: determining m physical resource block pairs used for transmitting a control channel to be transmitted, wherein an i th physical resource block pair comprises n i first physical resource elements, the i th physical resource block pair comprises k i second physical resource elements, and the second physical resource elements comprised in the m physical resource block pairs form multiple second physical resource element groups, wherein the first physical resource elements are used for transmitting the control channel to be transmitted in a localized transmission mode, the second physical resource elements are used for transmitting the control channel to be transmitted in a distributed transmission mode, and one of the n i first physical resource elements comprises at least two second physical resource elements, wherein m≥1, n i ≥1, k i ≥1, 0≤i≤m-1, and m, i, n i, and k i are all integers; when the control channel to be transmitted is transmitted in the distributed transmission mode, determining an aggregation level L of the control channel to be transmitted, wherein L≥1, and L is an integer; determining, according to the aggregation level L, the number G L of second physical resource elements comprised in each of the second physical resource element groups, wherein the G L second physical resource elements comprised in each of the second physical resource element groups are located in ┌G L / q┐ first physical resource elements in the m physical resource block pairs, wherein q indicates the number of second physical resource elements comprised in one of the n i first physical resource elements, ┌G L / q┐ indicates roundup of G L / q, G L ≥1, and G L is an integer; determining, according to the aggregation level L, a first control channel candidate at the aggregation level L, wherein the first control channel candidate corresponds to N L second physical resource element groups, wherein N L ≥1, and N L is an integer; and placing control information of the control channel to be transmitted, on physical resources to which the first control channel candidate is mapped, and transmitting the control information. determining m physical resource block pairs used for transmitting a control channel to be transmitted, wherein an i th physical resource block pair comprises n i first physical resource elements, the i th physical resource block pair comprises k i second physical resource elements, and the second physical resource elements comprised in the m physical resource block pairs form multiple second physical resource element groups, wherein the first physical resource elements are used for transmitting the control channel to be transmitted in a localized transmission mode, the second physical resource elements are used for transmitting the control channel to be transmitted in a distributed transmission mode, and one of the n i first physical resource elements comprises at least two second physical resource elements, wherein m≥1, n i ≥1, k i ≥1, 0≤i≤m-1, and m, i, n i, and k i are all integers; when the control channel to be transmitted is transmitted in the distributed transmission mode, determining an aggregation level L of the control channel to be transmitted, wherein L≥1, and L is an integer; determining, according to the aggregation level L, the number G L of second physical resource elements comprised in each of the second physical resource element groups, wherein the G L second physical resource elements comprised in each of the second physical resource element groups are located in ┌G L / q┐ first physical resource elements in the m physical resource block pairs, wherein q indicates the number of second physical resource elements comprised in one of the n i first physical resource elements, ┌G L / q┐ indicates roundup of G L / q, G L ≥1, and G L is an integer; determining, according to the aggregation level L, a first control channel candidate at the aggregation level L, wherein the first control channel candidate corresponds to N L second physical resource element groups, wherein N L ≥1, and N L is an integer; and placing control information of the control channel to be transmitted, on physical resources to which the first control channel candidate is mapped, and transmitting the control information.