Method for transmitting and receiving synchronization signal block in unlicensed band, and device therefor

Disclosed is a method by which a terminal receives a synchronization signal/physical broadcast channel (SS/PBCH) block in an unlicensed band. Particularly, the method comprises: receiving information related to an actual transmitted SS/PBCH block (ATSS) transmitted by a base station; and receiving the SS/PBCH block on the basis of valid bits from among a plurality of bits included in the information related to the ATSS, wherein the number of valid bits can be based on an interval value between SS/PBCH blocks capable of assuming a quasi co-location (QCL).