The utility model relates to a water-soluble PVA cast film production device, which solves the problem that the prior production method is unstable in ensuring continuous production. The device comprises a stirring kettle, a liquid storage tank and a buffer slot connected in series through a pipeline, wherein the bottom part of the buffer slot is connected with a strip-shaped liquid outlet groove, a regulating penetrates through the liquid outlet groove, a stainless steel conveying belt of a track conveyor is arranged in an oven in a penetrating manner, the two ends of the conveying belt correspond to the position of the liquid outlet groove and the position of a first heating roller set, a shaping roller set is arranged corresponding to the position of a last heating roller set, and a traction device and a winding device are arranged in sequence behind the shaping roller set. In the utility model, both the heating roller set and the shaping roller set contain an oil medium heating roller and a silicon rubber compaction roller. The surface of the silicon rubber compaction roller is a heat-proof silicon rubber layer, with the two ends connected with a pneumatic pressure regulation device; and the oil medium heating roller is a steel roller, and the heating mode adopts oil medium heating. The utility model can realize the continuous production of water-soluble PVA degraded films, thereby realizing industrial application.