The invention discloses a preparation method of a carbon nanoscroll/nano-silver composite antibacterial material. The preparation method comprises the steps that oxidized graphene is subjected to deprotonation treatment through sodium carbonate; the deprotonated oxidized graphene is mixed with a silver nitrate solution, and the mixture is evenly stirred, centrifuged, washed, frozen and dried; the oxidized graphene adsorbing silver ions is dissolved in water again, a NaBH4 water solution is slowly dropwise added with vigorous stirring to reduce the silver ions into nano-silver; and the mixed solution is ultrasonically treated in an ice-water mixed bath, and the carbon nanoscroll/nano-silver composite antibacterial material is prepared. The chemical reduction method and ultrasonic preparation under the ice-water mixed bath are adopted, the antibacterial performance and silver ion slow release performance of the oxidized graphene are effectively improved, the process is simple, operation is convenient, reaction conditions are mild, the production efficiency is high, and environmental friendliness is achieved.