A method of transmitting and receiving a PUSCH in a wireless communication system and a device therefor are disclosed. The method performed by a user equipment (UE) comprises receiving, from a base station (BS), configuration information including information for an uplink resource, information for a sequence, and information for sequence resources related to beams, determining a transmit (Tx) beam among the beams, transmitting, to the BS, the sequence in the sequence resource related to the Tx beam, and transmitting, to the BS, the PUSCH in the uplink resource based on the Tx beam in an RRC idle state or an RRC inactive state.