The present disclosure provides a method for transmitting or receiving a data channel in a wireless communication system, and an apparatus therefor. Specifically, a method for receiving a data channel by a user equipment (UE) in a wireless communication system may include: receiving downlink control information (DCI), wherein the DCI includes i) a transmission configuration indication (TCI) field and ii) an antenna port field; and receiving the data channel based on the DCI, wherein multiple TCI states are indicated on the basis of the TCI field, a demodulation reference signal (DM-RS) port is indicated on the basis of the antenna port field, and a repetition scheme of the data channel is determined on the basis of the number of code division multiplexing (CDM) groups including a DM-RS port in which the data channel is received.