The invention discloses an automatic packaging bag separating device. The automatic packaging bag separating device is characterized by comprising a machine frame, a separating device body, a verticalconveying device and a horizontal conveying device, wherein the separating device body, the vertical conveying device and the horizontal conveying device are arranged in the machine frame, the separating device body is used for separating packaging bags and then conveying the packaging bags to the vertical conveying device, the vertical conveying device is used for conveying the packaging bags tothe horizontal conveying device. According to the automatic packaging bag separating device, a turning plate is adopted for controlling the conveying direction of the packaging bags, an executing device is simple and easy to maintain, and the control is accurate; on the premise that the conversion rotation time interval of a planetary gear device is reasonably designed, complete automatic separation of the packaging bags can be realized, the separation efficiency of the packaging bags is improved, the labor and the volume of the devices are reduced; and meanwhile, by adjusting the conversionrotation time interval and the length of a horizontal conveying belt, the automatic packaging bag separating device can be widely applied to packaging bags with various sizes.