The invention provides an oily thermal reaction beef essence and a preparation method thereof. The essence is prepared from the following raw materials, by weight, 1-10 parts of reducing sugar, 1-15 parts of one or more than two amino acids, 0.1-5 parts of VB1, 0-5 parts of VC, 0.1-3 parts of I+G, 0.1-5 parts of spicy material powder, 0.5-1 part of a scallion paste, 0.5-1 part of a ginger paste, and 60-95 parts of grease. The essence obtained in the invention has the advantages of strong fragrance with the beef characteristic, full meat fragrance and rich taste.