A terminal device, comprising: a first acquiring unit, configured to acquire at least one group of physical random access channel, PRACH, configuration information that has been stored, wherein the at least one group of PRACH configuration information is carried in system information sent by a base station, wherein each group in the at least one group of PRACH configuration information is corresponding to a coverage enhancement level; a processing unit, configured to parse the at least one group of PRACH configuration information to obtain a corresponding start PRACH resource; and a first sending unit, configured to send a preamble to the base station starting from the start PRACH resource, so that the base station establishes a connection to the terminal device according to the preamble, wherein: the first acquiring unit is further configured to: acquire, on a PDCCH channel according to a specified random access radio network temporary identifier, RA-RNTI, calculation formula, downlink resource information sent by the base station; and receive a random access response, RAR, from the base station according to a channel specified by descrambled downlink resource information, wherein an msg3 is sent according to a quantity of repetition times corresponding to a repetition times index carried by the RAR, characterized by the specified RA-RNTI calculation formula comprising: RA-RNTI = 1 + t _ id + 10 ∗ f _ id + X wherein, X is an offset that corresponds to the respective coverage enhancement level, t_id and f id indicate a first PRACH resource or a last PRACH resource used when the preamble is repeatedly sent. a first acquiring unit, configured to acquire at least one group of physical random access channel, PRACH, configuration information that has been stored, wherein the at least one group of PRACH configuration information is carried in system information sent by a base station, wherein each group in the at least one group of PRACH configuration information is corresponding to a coverage enhancement level; a processing unit, configured to parse the at least one group of PRACH configuration information to obtain a corresponding start PRACH resource; and a first sending unit, configured to send a preamble to the base station starting from the start PRACH resource, so that the base station establishes a connection to the terminal device according to the preamble, wherein: the first acquiring unit is further configured to: acquire, on a PDCCH channel according to a specified random access radio network temporary identifier, RA-RNTI, calculation formula, downlink resource information sent by the base station; and receive a random access response, RAR, from the base station according to a channel specified by descrambled downlink resource information, wherein an msg3 is sent according to a quantity of repetition times corresponding to a repetition times index carried by the RAR, characterized by the specified RA-RNTI calculation formula comprising: RA-RNTI = 1 + t _ id + 10 ∗ f _ id + X wherein, X is an offset that corresponds to the respective coverage enhancement level, t_id and f id indicate a first PRACH resource or a last PRACH resource used when the preamble is repeatedly sent. the first acquiring unit is further configured to: acquire, on a PDCCH channel according to a specified random access radio network temporary identifier, RA-RNTI, calculation formula, downlink resource information sent by the base station; and receive a random access response, RAR, from the base station according to a channel specified by descrambled downlink resource information, wherein an msg3 is sent according to a quantity of repetition times corresponding to a repetition times index carried by the RAR, characterized by the specified RA-RNTI calculation formula comprising: RA-RNTI = 1 + t _ id + 10 ∗ f _ id + X wherein, X is an offset that corresponds to the respective coverage enhancement level, t_id and f id indicate a first PRACH resource or a last PRACH resource used when the preamble is repeatedly sent.