Abstract: The present disclosure relates to a method for preparing a fermented composition, and more specifically, to a method for preparing a fermented composition with improved odor, which comprises preparing grain flour; performing primary fermentation of the grain flour using yeast; performing secondary fermentation of the primary fermented product using a strain of the genus Bacillus; and obtaining the secondary fermented product. The fermented composition of the present disclosure has a high content of a peptide with a low molecular weight, and thus enables the increase of digestibility and absorption rate of proteins during ingestion while also improving the peculiar odor of a fermented product to enhance its palatability.