The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). The present disclosure provides a method for transmitting uplink control information, including: determining, by a user equipment (UE), at least two carriers for uplink transmission in a cell currently connected by the UE, and determining a carrier for uplink control information (UCI) transmission from the at least two carriers for uplink transmission; determining, by the UE, a relative frequency-domain position and a time-domain starting position occupied by UCI on the determined carrier for UCI transmission; and retuning, by the UE, a center radio frequency of the UE to a center frequency of the carrier for UCI transmission, and transmitting the UCI according to the relative frequency-domain position and the time-domain starting position occupied by the UCI; in which, the UE receives and transmits information on one carrier at one time. Using the present disclosure can efficiently transmit UCI. The present disclosure further discloses a method for requesting random access, which comprising steps of: determining a time division duplex (TDD) uplink time-domain resource; determining, according to the TDD uplink time-domain resource, a time-domain resource used for transmitting a narrowband physical random access channel (NPRACH); determining a time-domain format for an NPRACH transmission group, the time-domain format comprising: one NPRACH transmission group comprises at least two transmission units which are discontinuous in time domain, and one transmission unit comprises one or more NPRACH symbol groups which are continuous in time domain; and, determine time-domain resource used for transmitting NPRACH to transmit an NPRACH transmission group in the time-domain format. Compared with the prior art, in the present disclosure, a time-domain position for transmitting an NPRACH is designed according to the characteristics of TDD uplink time-domain resource, so that a random access process can be deployed within an LTE band or an LTE guard band; moreover, since an NB-IoT communication system based on TDD is used, a higher utilization rate of system spectrum resources is achieved.