The invention provides an improved PVC (Polyvinyl Chloride) film blowing machine and belongs to the technical field of film blowing machines, aiming at solving the problem in the prior art that the film blowing efficiency is low. The improved PVC film blowing machine comprises a base, wherein a mounting plate I and a mounting plate II, which are arranged in parallel, are fixedly arranged on the base; a mounting frame is detachably arranged between the mounting plate I and the mounting plate II; the base is provided with a melting mechanism capable of melting raw materials; a film blowing mechanism capable of blowing out a film material is arranged at one side of the melting mechanism; a cooling mechanism capable of cooling the film material is arranged below the film blowing mechanism; a traction roller III is arranged above the cooling mechanism; a cutting mechanism capable of cutting leftovers is arranged above the traction roller III; a recycling mechanism capable of recycling wastematerials is arranged above the cutting mechanism; a pressing roller I and a pressing roller II are further arranged between the mounting plate I and the mounting plate II; a material winding mechanism capable of winding the film material is arranged at one sides of the pressing roller I and the pressing roller II. The improved PVC film blowing machine has the advantage of high film blowing efficiency.