As one of the key macroeconomic indicators, the US Dollar Index (DXY) reflects the strength of the US dollar, but its fluctuations also have a series of cascading effects on global financial markets, including cryptocurrencies. This article will provide a comprehensive interpretation of the US Dollar Index, covering its basic concept, development history, influencing factors, and analyzing the relationship between the DXY and cryptocurrencies like Bitcoin. The goal is to offer valuable insights for crypto investors.