The invention relates to old oil hotpot flavor essential oil. The oil is prepared from, by weight, 40-80 parts of hotpot fresh oil, 15-30 parts of hotpot condiment extracts, 0.3-2 parts of butyric acid with mass concentration of 1%, 0.1-1 part of 2,5-dimethylpyrazine, 0.05-0.5 part of trans,trans-2,4-decadienal, 1-4 parts of furfural with mass concentration of 10%, 0.1-1 part of butyric acid butylester, 0.05-0.5 part of isovaleric acid with mass concentration of 1%, 0.1-1 part of ethyl acetate with mass concentration of 10%, 0.1-1 part of butyric acid butylester, 0.05-0.5 part of 2,3,5-trimethylpyrazine with mass concentration of 1%, 3-8 parts of furanone, 3-8 parts of ethyl maltol and the balance soybean oil supplemented till 100 parts. The essential oil is natural, safe and healthy, customers can enjoy the delicious taste, and meanwhile the requirement for ensuring body health can be met.