The invention discloses a fermentation bag for mouldy spot appearing of a Fuzhuan tea surface; the fermentation bag includes an inner film layer, an intermediate film layer and an outer film layer; the inner film layer is a hydrophilic film layer, the outer film layer is a hydrophobic film layer, the intermediate film layer is an air permeable film layer, and the inner film layer, the intermediate film layer and the outer film layer are molded through bonding extrusion. With use of the fermentation bag provided by the invention, after Fuzhuan tea is subjected to fermentation treatment, the interior of the Fuzhuan tea has eurotium cristatum, the eurotium cristatum also grows on the Fuzhuan tea surface, and the eurotium cristatum at the interior of the Fuzhuan tea and on the surface of the Fuzhuan tea are distributed uniformly, the nutritional value of the product is improved, and the product quality is enhanced.