The invention provides low-sugar longan pomace jam capable of maintaining beauty and keeping young and a preparation method of the low-sugar longan pomace jam. The jam is prepared from the following ingredients: longan pomace, pitted red dates, honey, desalted whey protein, dried mulberries, black fungi, collagen peptide, fructus lycii, poria cocos powder, yam flour, low-methoxy pectin, D-sodium erythorbate, CaCl2, citric acid and vitamin C. The preparation method comprises the following process steps of: pretreating raw materials, softening the materials, refining, mixing, boiling, filling, sterilizing and cooling. The low-sugar longan pomace jam capable of maintaining beauty and keeping young is fine in texture, sour, sweet and delicious in taste, outstanding in flavor and attractive in color, is rich in vitamin C, polysaccharide and polyphenol, contains nutritional ingredients such as dietary fiber, protein, calcium, potassium, magnesium and iron, and has the effects of maintaining beauty and keeping young, replenishing Qi and enriching blood and enhancing immunity.