The purpose of this article is to analyze BigHit's BTS success strategy and fandom ARMY in the process of gaining global fame as a world star with Korean idol's popular music, especially BTS music. This research analysis focuses on the three-way interaction between BigHit and BTS and Fandom ARMY. It is analyzed that the success of BTS and the formation of a global fandom were the result of CEO Bang Si-hyuk's creation of a small and medium-sized agency called BigHit, making BTS ranked on the Billboard Hot 100 and Billboard 200, respectively. Research focus is centered on the research value that led to the passion and tenacity of the BigHit organization and its representative Bang Si-hyuk, but I would to additional explain that BTS music has focused on BTS success or its corresponding fandom. Its research background is attempts a theoretical overview to a prior study of BTS, Bang Si-hyuk and BigHit's organizational form, the birth of BTS and its members, etc. After all, CEO Bang Si-hyuk's success strategy are analyzed mainly Youtube or Music Video(MV) of SNS from 2013 to 2017 about influence on the BigHit organization, the birth of BTS, the BTS success method, and BTS' fandom (ARMY). In conclusion, it summarizes BigHit's BTS success strategy and BTS' success factors that can affect K-pop idols in the future.