The invention discloses a longan drink and a preparation method thereof. The longan drink is prepared from 1000-3000 parts of longan pulp, 100-300 parts of sucrose, 1-20 parts of yeasts, 1-10 parts of sulfur dioxide, 1-50 parts of citric acid and 30-50 parts of pectinase. The preparation method comprises the following steps of 1) adding sulfur dioxide to the longan pulp, and breaking and squeezing the mixture to extract juice; 2) adding the citric acid to the prepared longan juice to regulate the total acid to be 3-5g/L, and then adding pectinase for enzymolysis and clarification; 3) adding the sucrose and the yeasts to the longan juice after enzymolysis and clarification, and fermenting the longan juice at 30-35 DEG C for 1-5 hours; and 4) blending the liquid obtained by fermentation with water, and then carrying out sterilization, thus obtaining the longan drink. The longan drink takes longans as main raw materials, has low alcohol content, moderate sweetness and good taste, and has unique aroma emitted by the longans.