The invention discloses a R744 air conditioner rubber tube. In the R744 air conditioner rubber tube, a nylon-polyvinyl alcohol-nylon three-layer composite is adopted as a barrier layer, and through the adoption of the barrier layer structure of the three-layer composite, the permeability of the air conditioner rubber tube for R744 working mediums can be reduced; particularly, the polyvinyl alcohol layer in the barrier layer has good penetration resistance, so that the mechanical strength of the barrier layer can be improved while the barrier effect is improved; and besides, in a preparation method disclosed by the invention, the nylon-polyvinyl alcohol-nylon three-layer composite is adopted as the barrier layer, so that the prepared rubber tube has the advantages of being low in permeability, high in bursting pressure, and the like.