The invention discloses a polylactic acid film manufacturing device. A winding device of the polylactic acid film manufacturing device comprises a winding rack, a winding mandrel, a friction roller arranged at the lower part of the winding rack, a lifting sling arranged at the top part of the winding rack, shaft releasing mechanisms which are arranged on rack wallboards on two sides of the windingrack, sliding shaft mechanisms arranged at the outer sides of the two ends of the friction roller, and a pulling mechanism arranged in front of the friction roller; and the friction roller is a rubber roller, the surface of the friction roller is provided with a groove with a continuous rhombic pattern, the diameter of the groove is 380-400 mm, and a film pressing roller is further arranged behind the friction roller. According to the polylactic acid film manufacturing device, the winding mandrel can be conveniently placed to be in contact with the friction roller and can unload a winded heavy film roll from the winding mechanism, the problem that the polylactic acid film is not easy to flatten is overcome, so that quality of the finally prepared polylactic acid film is guaranteed, and inaddition, a water removal device is improved so that water on the surface of the film can be removed before corona treatment.