The invention provides jasmine tea fermented beer and a preparation method thereof, and relates to the technical field of bear brewage. The preparation method provided by the invention comprises the following steps of: carrying out saccharification, i.e., mixing malt with water, raising the temperature to 44 DEG C to 46 DEG C, carrying out heat preservation for preset time, raising the temperatureto 61 DEG C to 63 DEG C, carrying out heat preservation for preset time, raising the temperature to 72.5 plus and minus 0.5 DEG C, carrying out heat preservation for preset time, raising the temperature of 78 plus and minus 0.5 DEG C, and carrying out saccharification to obtain saccharification liquor; carrying out cooking, i.e., filtering the saccharification liquor to obtain clarified wort, boiling the wort, and adding hops to obtain hot wort; carrying out cooling, i.e., carrying out clarification on the hot wort and performing cooling to obtain cold wort; carrying out fermentation, i.e., oxygenating the cold wort, adding yeast to carry out fermentation, so as to obtain wine liquid after a fermenting state that the diacetyl content is smaller than or equal to 0.15ppm is reached; and carrying out cold extraction, i.e., cooling the wine liquid to a temperature of 5 DEG C to 8 DEG C, and carrying out cycle extraction on jasmine tea by the wine liquid so as to obtain the jasmine tea fermented beer. The bear obtained by the preparation method provided by the invention is proper and stable in content of a polyphenol substance, and has the advantages of low bitterness and no generationof turbidness after long-time storage.