Preparation device and preparation method of composite asphalt binder

The invention discloses a composite asphalt binder preparation device and a preparation method thereof, which are applied to the technical field of asphalt binder preparation, a mixing barrel is arranged to be matched with an auxiliary box, and a power part in the auxiliary box can drive an inner barrel to rotate in the mixing barrel, so that the inner barrel can centrifugally rotate after a mixed material is contained in the inner barrel; a stirring shaft can be driven by a first motor at the top of the top cover to rotate for mixing, flexible selection according to the mixed materials and actual conditions can be facilitated by selecting multiple mixing modes, the arranged filling assembly can put the materials into a temporary storage barrel during material filling, and the materials are pumped into a plurality of branch filling pipes through a liquid pump, so that the filling efficiency is improved; and the mixture is injected into the inner cylinder through the one-way valve and is directly injected into