Method and apparatus for one cell operation with fast small cell switching in wireless communication system

The present invention relates to a method for supporting fast sub-cell switching in a wireless communications system. A method for supporting fast sub-cell switching by a sub-cell included in a macro coverage in the wireless communications system comprises: a reception step of receiving multiple pieces of feedback information on multiple sub-cells from user equipment (UE); an extraction step of extracting channel quality indicators from the multiple pieces of received feedback information, respectively; and a determination step of comparing values of the extracted channel quality indicators and determining whether to perform fast sub-cell switching of the UE based on a result of the comparison.