The invention discloses a film blowing device for highly-filled plastic films, and the film blowing device comprises an extruder, a blow molding die head, a cooling device, a traction apparatus and a finished film rolling device, wherein the extruder has high plasticizing property; the cooling device is provided with a cooling vane and an internal cooling device; the traction apparatus is composed of a gable and a traction roller; meanwhile, the film blowing device also comprises a melt metering pump; and the high-plasticization extruder, the melt metering pump and the blow molding die head are sequentially connected in a same horizontal plane, the cooling vane is vertically arranged above the blow molding die head, the internal cooling device is also arranged above the blow molding die head, the traction apparatus is also arranged above the cooling device, and the finished film rolling device is arranged below one side of the traction apparatus and located opposite to the high-plasticization extruder. The film blowing device for highly-filled plastic films disclosed by the invention can be applied to plastic composites which are subjected to intensive mixing but not subjected to extrusion granulation so as to directly prepare films with high filler content through blowing.