The smooth degree of the filter medium surface has the great effect to the dynamic function resistance to the filter medium. The initial resistance of the filter medium decides the air permeability of the filter medium itself, but the resistance during operating is several times to the initial resistance. The operating resistance depends on the smooth degree of the filter medium surface and the dedusting effect. In general, the better the larger air permeability and the better the lower operating resistance when people guarantee the same filtration effect, which can reduce the energy. During using the air reverse blowing dedusting precipitator, under the same pressure and the air volume condition, it is better by selecting the large air volume woven than the smaller.Therefore, it is the first solved problem that how can improve the air permeability, smooth degree and reduce the dust adherence, operating resistance. The needle punched filter felt with smooth surface resin treatment developed by us,its air permeability is 50% higher than the common calendaring treatment and the smooth degree is better than the calendaring treatment. The order of the air permeability of the same precision clean filter medium tested in the laboratory is: singeing treatment filter medium easily ded-usting treatment filter medium common calendaring filter medium. In actual operation resistance, the order from big to small is: easily dedusting treatment filter medium singeing treatment filter medium common calendaring filter medium. It is the aim with smooth filter medium surface, good air permeability, and low operating resistance for the filter medium manufacturing plant. It is the first choice of the easily dedustingneedle punched filter felt for the filter medium experts