Preparation method of pinhole-free PVDC casing film

The invention relates to the technical field of packing materials, and particularly discloses a pinhole-free PVDC casing film preparation method, which specifically comprises: placing PVDC resin and EVA resin in a mixing machine, and starting mixing and heating; adding the heat stabilizer, the DBS plasticizer, the lubricant and the pigment when the mixture is heated to 40-45 DEG C, and continuing mixing and heating; when heating to 80-85 DEG C, stopping heating, continuously mixing, discharging, and curing at room temperature; s2, placing the cured mixture in the step S2 in a screw extruder for melt extrusion, blowing to form a blank, and drawing to form a film; and feeding into a drying oven at 105-110 DEG C for 20-30 minutes, and then rolling. The VA content of the EVA resin is strictly controlled to be 28 +/-2%, the EVA resin is well compatible with the PVDC resin, the crystallization speed and crystallinity are properly reduced, and the casing film which is good in low-temperature toughness, high in stren