The invention relates to a production line and production technology of flat filaments of flexible freight bags, and belongs to the technical field of packaging supply production. The production line of the flat filaments of the flexible freight bags comprises a stirring device, a melting and conveying device, an extrusion device, a cooling pond, a cutting device, a folding device, a hot stretching device, a heat setting device and a winding device which are arranged in sequence, wherein the cutting device comprises an upper roller and a lower roller which are horizontally arranged, the upper roller and the lower roller rotate oppositely and reversely, the upper roller slides up and down, multiple annular bulges are fixedly arranged on the upper roller, gaps are formed among the annular bulges, annular blades are fixedly connected with the positions, corresponding to the gaps, of the lower roller, and the annular blades are embedded into the gaps. According to the production line and production technology of the flat filaments of the flexible freight bags, cooled membranes are made to pass through space between the upper roller and the lower roller, the upper roller is made to slide downwards, thus the annular blades are embedded into the gaps, through cooperation of the annular blades and the annular bulges, each membrane can be cut and folded into a long strip shape with two sides turned upwards, operation is convenient and quick, functions of cutting and preliminary folding are achieved at the same time, the technology is simplified, and the operation is more convenient and quicker.