The invention discloses a preparation method of sterile honey, and particularly relates to the technical field of honey processing. The preparation method comprises multiple procedures of rough filtration, sterilization, purification, concentration and sterile canning, raw honey of honey is subjected to rough filtration to filter out large-particle impurities, then high-density CO2 is introduced for sterilization, and after sterilization, ultrafiltration purification is performed to achieve the effects of further sterilization, impurity removal and peculiar smell removal, so that the sterilization rate reaches 99% or above; soluble soybean polysaccharide and nano cellulose are added into honey clarified liquid obtained through ultrafiltration to serve as stabilizers, so that honey can be kept clarified and bright in color, dietary fibers are increased, the taste is cleaner, sweet and pure, the uniformity and stability of a honey finished product are further improved, vacuum concentration is conducted after ultrafiltration, and finally sterile canning storage is conducted. The sterile honey finished product obtained by adopting the method maximally retains nutrient substances and natural flavor of raw honey, avoids precipitation of the honey finished product, improves the quality of the honey, and prolongs the storage life.