A method for receiving a downlink channel by a terminal in a wireless communication system and a device therefor. More particularly, a method includes: receiving, from a base station, configuration information relating to a plurality of transmission beams of the base station, wherein the configuration information includes configuration items with respect to one or more beam sets including the plurality of transmission beams; receiving information indicating any one beam set among the one or more beam sets from the base station; and receiving a downlink control channel from the base station based on the indicated beam set, wherein, if the information indicating any one beam set is not received from the base station, the downlink control channel can be received based on a pre-configured beam set among the beam sets.