Embodiments of the present disclosure provide control information sending methods, control information receiving methods, and devices. The sending method may include determining, by an access network device, a control channel candidate set corresponding to a terminal device, where the control channel candidate set includes at least one control channel candidate, the at least one control channel candidate includes at least one control channel element, the control channel candidate set is contained in at least one control channel element set, a quantity of control channel elements contained in the control channel element set is greater than or equal to a quantity of control channel elements corresponding to a maximum aggregation level supported by the terminal device. The sending method may further includes sending, by the access network device, control information to the terminal device by using at least one control channel candidate in the control channel candidate set. The control information sending method of the embodiments of the present invention can satisfy requirements of new generation radio communications systems.