The invention discloses tom yum kung essence and a preparation method thereof. The tom yum kung essence is prepared from the following components: citronella oil, curry oil, lemon oil, cold pressed ginger oil, chili oil, 1-octene-3-alcohol, dimethyl disulfide, tetrahydropyrrole, 2-acetylpyridine, 4-methyl-5-beta-hydroxyethyl thiazole, pyridine, trimethylamine, 2-methyl-3(5 or 6)-methylthiopyrazine, cis-4-heptenal, nutmeg oil, dimethyl sulfide, an anti-oxidizing agent and salad oil. The preparation method of the tom yum kung essence comprises the steps that the citronella oil, the curry oil, the lemon oil, the cold pressed ginger oil, the chili oil, the 1-octene-3-alcohol, the dimethyl disulfide, the tetrahydropyrrole, the 2-acetylpyridine, the 4-methyl-5-beta-hydroxyethyl thiazole, the pyridine, the trimethylamine, the 2-methyl-3(5 or 6)-methylthiopyrazine, the cis-4-heptenal, the nutmeg oil, the dimethyl sulfide and the anti-oxidizing agent are weighed and added to the salad oil, andthe mixture is stirred evenly to get the tom yum kung essence.