The invention provides a citrus fruit preservative which is composed of the following components in parts by mass: 3-5 parts of sucrose ester, 1-1.4 parts of sodium glutamate, 0.8-1.2 parts of citric acid, 0.3-0.5 part of sodium acetate, 0.02-0.03 part of potassium permanganate, 0.02-0.03 part of sodium chloride and 170-175 parts of water. The invention also provides a preparation method of the citrus fruit preservative, which comprises the following steps: mixing the sucrose ester, citric acid and water according to the formula, thoroughly mixing for 10-15 minutes, heating to 45-50 DEG C, adding the sodium glutamate, sodium acetate and sodium chloride according to the formula, stirring for 8-12 minutes, cooling to room temperature, adding the potassium permanganate according to the formula, and stirring uniformly. The citrus fruit preservative has the advantages of simple preparation method, reasonable formula, low cost, uniform effect and favorable preservation effect, and is convenient to operate; and compared with other preservatives sold in the market, the preservation period is prolonged by more than 22%.