The invention discloses a preparation method of a beer bottle sterilizing detergent based on a microcrystalline cellulose/silver composite material. A nanocrystalline cellulose suspension prepared byan enzymatic method is mixed with silver nitrate and then a hydrothermal synthesis reaction is carried out to obtain a nano-silver loaded nano microcrystalline cellulose suspension, a biological surfactant, alkali and other raw materials are added and uniform mixing is carried out to obtain the beer bottle sterilizing detergent. The beer bottle sterilizing detergent prepared by the preparation method not only has the advantages of strong detergency, good anti-dirt redeposition ability, easiness for rinsing and removing dirt, and good cleaning effect on beer bottles, and can reduce scaling of equipment and is favorable for smooth running of a whole system, but also synchronously achieves sterilization and disinfection of the beer bottles with good bactericidal effect, and effectively improves the hygiene performance of the cleaned beer bottles.