A control information sending method, comprising: receiving, by a base station, a first signaling from a first user equipment, wherein the first signaling carries an identifier of the first user equipment and information about a preamble sequence, and the identifier is used for random access between the first user equipment and the base station; and sending, by the base station, a second signaling to the first user equipment and a second user equipment, wherein the second signaling carries information about a user equipment cooperation group, and the user equipment cooperation group comprises the first user equipment and the second user equipment; characterized in that the preamble sequence is used for random access between the first user equipment and the second user equipment and is received by the first user equipment from the second user equipment; and wherein the information about the preamble sequence comprises information about a time-frequency resource occupied by the preamble sequence; wherein the time-frequency resource information includes a subframe number t_id of a first subframe in a subframe occupied by a device-to-device, D2D, random access preamble sequence and a sequence number f_id of a first resource block, RB, in a frequency band occupied by the D2D random access preamble sequence; obtaining, by the base station, notification by the first user equipment about the time-frequency resource of a received D2D random access preamble by using a message 3; and and obtaining, by the base station, based on the f_id and the t_id, through calculation, a temporary identifier of an random access response, RAR, required when an RAR is sent; wherein the first user equipment is a neighboring user equipment, NUE, and the second user equipment is a target user equipment, TUE; and wherein the sending comprises sending, by the base station, a D2D random access response, D2D RAR, to the TUE and the NUE; wherein the D2D RAR includes a group identifier allocated by the base station for the user equipment cooperation group; determining, by the base station, based on the message 3 received from the NUE, that the NUE provides cooperation for the TUE, or that the NUE becomes cooperation user equipment, CUE, of the TUE; wherein the TUE has one or more neighboring user equipments that can provide the cooperation for the TUE, and the TUE and all the neighboring user equipments that may become the CUE of the TUE form the user equipment cooperation group. receiving, by a base station, a first signaling from a first user equipment, wherein the first signaling carries an identifier of the first user equipment and information about a preamble sequence, and the identifier is used for random access between the first user equipment and the base station; and sending, by the base station, a second signaling to the first user equipment and a second user equipment, wherein the second signaling carries information about a user equipment cooperation group, and the user equipment cooperation group comprises the first user equipment and the second user equipment; characterized in that the preamble sequence is used for random access between the first user equipment and the second user equipment and is received by the first user equipment from the second user equipment; and wherein the information about the preamble sequence comprises information about a time-frequency resource occupied by the preamble sequence; wherein the time-frequency resource information includes a subframe number t_id of a first subframe in a subframe occupied by a device-to-device, D2D, random access preamble sequence and a sequence number f_id of a first resource block, RB, in a frequency band occupied by the D2D random access preamble sequence; obtaining, by the base station, notification by the first user equipment about the time-frequency resource of a received D2D random access preamble by using a message 3; and and obtaining, by the base station, based on the f_id and the t_id, through calculation, a temporary identifier of an random access response, RAR, required when an RAR is sent; wherein the first user equipment is a neighboring user equipment, NUE, and the second user equipment is a target user equipment, TUE; and wherein the sending comprises sending, by the base station, a D2D random access response, D2D RAR, to the TUE and the NUE; wherein the D2D RAR includes a group identifier allocated by the base station for the user equipment cooperation group; determining, by the base station, based on the message 3 received from the NUE, that the NUE provides cooperation for the TUE, or that the NUE becomes cooperation user equipment, CUE, of the TUE; wherein the TUE has one or more neighboring user equipments that can provide the cooperation for the TUE, and the TUE and all the neighboring user equipments that may become the CUE of the TUE form the user equipment cooperation group.