Four-stage porous PET non-woven fabric for filtering as well as preparation method and application thereof

The invention discloses a four-stage porous PET non-woven fabric for filtering. The non-woven fabric with a four-stage pore diameter structure of micropores, mesopores, macropores and super-macroporesis prepared from porous PET fibers, and the porous PET fibers are PET fibers with three-stage pore structures in which the micropores, the mesopores and the macropores are disorderly distributed. Theinvention also discloses a preparation method of the non-woven fabric. The method comprises the following steps of dissolving PET by using a low-melting-point organic solvent through a low-temperature dissolving method, carrying out melt-blowing lapping, carrying out hot air drying, and finally carrying out hot rolling to obtain the four-stage porous PET non-woven fabric for filtering. The four-stage porous PET non-woven fabric for filtering can be used for precisely filtering waste water and waste gas, and is particularly applied to filtering of high-temperature liquid and high-temperature gas; and the four-stage por