Abstract: The invention discloses a fiber filament non-woven fabric with a small pore size and a large porosity, which adopts an island type ultra-fine fiber single filament, which is juxtaposed into an unidirectional silk layer several times, and a thin strip-shaped liquid is applied laterally on the unidirectional silk layer. The resin adhesive liquid bonds and fixes all the silk layers into a unidirectional non-woven fabric fixed in a grid segment. The unidirectional non-woven fabric is covered with meltblown non-woven fabric on one or both sides to make a filter material that can 100% filter viruses, bacteria, and micro-particles smaller than PM2.5. It can also be used for a wider range of filter materials, thermal insulation materials, oil absorption materials, battery separator materials, medical and health materials, environmental protection materials, clothing materials, wiping materials.