The invention provides a cosmetic containing custard apple multiple fermentation liquor and a preparation method thereof, and belongs to the technical field of cosmetics. Aiming at component analysis and fermentation process exploration of annona squamosa fruit fermentation liquor, fermentation liquor of different stages is obtained one by one through batch fermentation, the fermentation synergistic effect of fermentation strains is explored to improve the effect of the fermentation liquor, the annona squamosa fruit multiple fermentation filtrate is obtained, and the fermentation liquor belongs to natural plants, is rich in nutrition, is not prone to allergy, is safe and reliable, has a good moisturizing effect, and can effectively scavenge free radicals, inhibit tyrosinase and reduce melanin, so as to achieve the whitening purpose. Bacterial strains used in the fermentation process are reliable in source, easy to obtain, free of pathogenic bacteria and mostly human intestinal probiotics, the preparation method is simple, organic reagent residues are avoided, and the fermentation liquor has the effects of being easy to be absorbed, moisturizing, whitening and improving the skin condition, can serve as an effective raw material additive to be applied to the cosmetic, is wide in application and has great market value.