A control information sending method applied to a Machine to Machine, M2M, cellular communication system, wherein in a scenario in which at least two control channels exist, the method comprises: determining (S100,S600), by user equipment, to change an accessed control channel from a first control channel to a second control channel, wherein the user equipment is a wireless terminal; and sending (S101,S601), by the user equipment, indication information of the second control channel to a network side device, wherein the network side device is a radio access network side device, so that the network side device sends control information to the user equipment over the second control channel according to the indication information of the second control channel; wherein the determining, by the user equipment, to change an accessed control channel from a first control channel to a second control channel comprises: measuring, by the user equipment, signal strength, wherein the signal strength is reference signal strength of a cell in which the user equipment is currently located, or signal strength of the first control channel; and determining, by the user equipment, to change the accessed control channel from the first control channel to the second control channel, if the signal strength is lower than a preset first threshold of the first control channel and higher than a preset second threshold of the second control channel; wherein the sending, by the user equipment, indication information of the second control channel to a network side device comprises: sending, by the user equipment, the indication information to the network side device if a current moment is within a preset report timeslot; or skipping sending the indication information to the network side device until a report timeslot arrives, if a current moment is not within the report timeslot. determining (S100,S600), by user equipment, to change an accessed control channel from a first control channel to a second control channel, wherein the user equipment is a wireless terminal; and sending (S101,S601), by the user equipment, indication information of the second control channel to a network side device, wherein the network side device is a radio access network side device, so that the network side device sends control information to the user equipment over the second control channel according to the indication information of the second control channel; wherein the determining, by the user equipment, to change an accessed control channel from a first control channel to a second control channel comprises: measuring, by the user equipment, signal strength, wherein the signal strength is reference signal strength of a cell in which the user equipment is currently located, or signal strength of the first control channel; and determining, by the user equipment, to change the accessed control channel from the first control channel to the second control channel, if the signal strength is lower than a preset first threshold of the first control channel and higher than a preset second threshold of the second control channel; wherein the sending, by the user equipment, indication information of the second control channel to a network side device comprises: sending, by the user equipment, the indication information to the network side device if a current moment is within a preset report timeslot; or skipping sending the indication information to the network side device until a report timeslot arrives, if a current moment is not within the report timeslot. measuring, by the user equipment, signal strength, wherein the signal strength is reference signal strength of a cell in which the user equipment is currently located, or signal strength of the first control channel; and determining, by the user equipment, to change the accessed control channel from the first control channel to the second control channel, if the signal strength is lower than a preset first threshold of the first control channel and higher than a preset second threshold of the second control channel; wherein the sending, by the user equipment, indication information of the second control channel to a network side device comprises: sending, by the user equipment, the indication information to the network side device if a current moment is within a preset report timeslot; or skipping sending the indication information to the network side device until a report timeslot arrives, if a current moment is not within the report timeslot.