The invention discloses a guava leaf health-care product capable of reducing blood sugar. Raw materials of the guava leaf health-care product comprise the following components in parts by mass: 20-40parts of guava leaves, 30-50 parts of bitter gourds, 30-50 parts of mulberry leaves, 10-30 parts of Chinese wolfberry fruits and 10-30 parts of ganoderma lucidum spore powder. The raw materials are all medicinal and edible substances having the efficacy of reducing blood sugar, and are safe, effective, low in price and suitable for long-term usage. Animal function study test proves that the functional health-care product capable of reducing blood sugar has the health-care function of assisting in reducing blood sugar, and is suitable for diabetes to take for a long term. The invention furtherdiscloses a preparation method of the guava leaf health-care product capable of reducing blood sugar. The preparation method comprises the following steps of preparing extractum by using water and ethanol as solvents, performing spray drying to obtain extractum powder, processing the extractum powder into tablets or capsules, and then performing coating so as to obtain the functional health-care product capable of reducing blood sugar. The operation is simple and convenient, the cost is low, large-scale industry production is performed easily, and the product is smooth and level in appearanceand can be stored for a long term.