The present disclosure relates to a method carried out by a user equipment in a wireless communication system and a device supporting same and, more particularly, to a method and a device supporting same, the method comprising the steps of: transmitting a physical random access channel (PRACH) preamble in at least one among a plurality of valid PRACH occasions in a PRACH slot; and in response to the PRACH preamble, obtaining information related to a random access response (RAR), wherein the PRACH preamble is included in a plurality of PRACH preambles related to the plurality of valid PRACH occasions, and on the basis that a plurality of consecutive PRACH preambles included in the plurality of PRACH preambles are mapped to a valid physical uplink shared channel (PUSCH) occasion, the plurality of PRACH preambles are mapped to first PUSCH occasions among a plurality of valid PUSCH occasions.