A random access channel, RACH, resource selection method, applied to user equipment and comprising: receiving RACH resource configuration information sent by a network-side device; after a random access process is triggered, selecting, based on obtained RACH resource configuration information, a physical random access channel, PRACH, transmit unit used for sending a preamble or a preamble and data; wherein the method is characterized in that the RACH resource configuration information comprises at least one of the following: a time window corresponding to PRACH transmit units available for selection, wherein a first PRACH transmit unit in the time window is a first valid PRACH transmit unit after the random access process is triggered; and N PRACH transmit units available for selection, wherein a first PRACH transmit unit in the N PRACH transmit units is a first valid PRACH transmit unit after the random access process is triggered, and N is a positive integer; wherein the RACH resource configuration information further comprises at least one of the following: a probability of selecting a PRACH transmit unit from the time window; and a probability of selecting a PRACH transmit unit from the N PRACH transmit units. receiving RACH resource configuration information sent by a network-side device; after a random access process is triggered, selecting, based on obtained RACH resource configuration information, a physical random access channel, PRACH, transmit unit used for sending a preamble or a preamble and data; wherein the method is characterized in that the RACH resource configuration information comprises at least one of the following: a time window corresponding to PRACH transmit units available for selection, wherein a first PRACH transmit unit in the time window is a first valid PRACH transmit unit after the random access process is triggered; and N PRACH transmit units available for selection, wherein a first PRACH transmit unit in the N PRACH transmit units is a first valid PRACH transmit unit after the random access process is triggered, and N is a positive integer; wherein the RACH resource configuration information further comprises at least one of the following: a probability of selecting a PRACH transmit unit from the time window; and a probability of selecting a PRACH transmit unit from the N PRACH transmit units. a time window corresponding to PRACH transmit units available for selection, wherein a first PRACH transmit unit in the time window is a first valid PRACH transmit unit after the random access process is triggered; and N PRACH transmit units available for selection, wherein a first PRACH transmit unit in the N PRACH transmit units is a first valid PRACH transmit unit after the random access process is triggered, and N is a positive integer; wherein the RACH resource configuration information further comprises at least one of the following: a probability of selecting a PRACH transmit unit from the time window; and a probability of selecting a PRACH transmit unit from the N PRACH transmit units. a probability of selecting a PRACH transmit unit from the time window; and a probability of selecting a PRACH transmit unit from the N PRACH transmit units.