The unique quality and health benefits of Fuzhuan brick tea primarily rely on the metabolic regulation by the "golden flower fungus" (Eurotium cristatum) during the "fahua" process. To deepen the understanding of their intrinsic connection, this review synthesizes the succession patterns and regional characteristics of the microbial community in Fuzhuan brick tea fermentation. It summarizes the mechanisms by which core microorganisms (e.g., E. cristatum, Bacillus spp.) regulate the transformation of tea components through enzymatic reactions (e.g., polyphenol oxidase, cellulase) and secondary metabolism (e.g., anthraquinones, polysaccharides): On one hand, they drive the oxidation of tea polyphenols and the synthesis of volatile compounds, shaping the characteristic "rich fungal aroma, bright reddish liquor color, and mellow taste" quality. On the other hand, their metabolites (e.g., Fu brick tea elements, tea polysaccharides) modulate the gut microbiota and inhibit oxidative stress, thereby exerting health effects such as anti-obesity and reduced metabolic disorder risks. This review provides a theoretical foundation for optimizing Fu brick tea quality and exploring the development of functional products based on "golden flower fungus" metabolites.