The production process is simple, with "one-step spinning" and "two-step spinning". Fibers are produced by polymerization of propylene as raw material, modification of the raw material, melt spinning, melt filtration, blow cooling, winding, and production. Compared with the production process of two-step spinning, one-step spinning has the characteristics of less land occupation, fewer personnel, and lower cost. The problem is that the strength of polypropylene fibers produced by one-step spinning is relatively low. Therefore, the modification of its raw materials is very important, and currently, the manufacturing method of polypropylene strong filament is commonly used. Its characteristic is to use polypropylene resin with melt flow index MFI=5-40 and molecular weight distribution index MWD<7, which is spun at a speed of 400-1600/minute to form. Then, two-stage traction and twisting are carried out on a spindle type traction and twisting machine to produce high-strength polypropylene filament with a composite fiber size of 400-1600 minutes.