Use Vat Photopolymerization as the technology. The increasing of the peeling angle is used to reduce the force of part separation. The developed bottom-up 3D printing system is capable to print large objects.A special control method for active release is proposed, which uses a flexible light-transmitting film as the core, and is controlled by an exhaust pump. When processing is performed, the release film can actively produce a larger peeling angle to achieve The phenomenon of peeling occurs, so that the fineness of its large workpieces can be maintained during printing, and the workpieces of various complex structures can be completed.Due to the relationship between the force of part separation of the larger workpieces on the market, almost all adopt the up-bottom 3D printing system, but the up-bottom type consumes a large amount of resin, resulting in excessive cost, and this bottom-illumination molding machine, by changing The release method of the resin tank can effectively reduce the generation of the large-area force of part separation, so that consumers can use the more economical raw material costs to form large objects.