Disclosed are Aspergillus oryzae aged cheese and a preparation method thereof, wherein the preparation method of the Aspergillus oryzae cheese comprises the following steps: (1) inoculating raw milk after sterilization with lactic acid bacteria fermentation agent and Aspergillus oryzae spore powder, fermenting to a pH value of 6.3-6.5, wherein an additive amount of the Aspergillus oryzae spore powder is 0.001‰-0.008‰‰ of a mass of the raw milk; (2) adding rennin and obtaining curd after curding; (3) cutting the curd to obtain curd blocks; and (4) moulding the curd blocks after expelling whey, and performing pickling and maturing after demoulding, wherein 1-7 days are taken for maturing under 20-30° C.; 7-15 days are taken for maturing under 15-20° C.; 10-20 days are taken for continuing maturing under 8-12° C.; and relative humidity of an environment for maturing is 85%-95%.