The present invention discloses grapefruit synthetic and active enzymes and a preparation method thereof, and relates to biological enzymes. The grapefruit synthetic and active enzymes consist of the following raw materials in parts by 
mass: 25-30 parts of grapefruits, 5-8 parts of lemons, 5-10 parts of minced tea, 1-3 parts of haws, 1-4 parts of traditional Chinese medicinal materials, 10-15 parts of yellow rice 
wine, 10-15 parts of red granulated 
sugar and 0.1-0.5 part of 
acetic acid bacterium. The preparation method of the grapefruit synthetic and active enzymes is as follows: 1) the fruit peels and fruit fleshes of the grapefruits are separated to obtain the grapefruit skins and grapefruit fleshes; 2) the grapefruit skins are 
cut into blocks, the yellow rice 
wine is added into the 
cut grapefruit 
skin blocks to be soaked, the soaked grapefruit 
skin blocks are distilled, water is added, and the grapefruit 
skin blocks are prepared into grapefruit skin 
wine; and 3) the obtained grapefruit fleshes obtained in the step 1) and the lemons are 
cut and crushed, the crushed materials are ground into 
slurry to obtain grapefruit and lemon fruit 
slurry, then the minced tea, red granulated 
sugar, haws, traditional Chinese medicinal materials, 
acetic acid bacteria and the grapefruit skin wine obtained in the step 2) rare successively added, the materials are blended evenly, the mixture is fermented, and the fermented mixture is filtered to obtain the grapefruit synthetic and active enzymes.