The electret materials are widely applied to such field as efficient low-resistance air filtering materials. The air filtering materials of electret require a large density, a long service life and a high stability for the electric charge for material storage. The raw materials of electret shall have superior dielectric properties, such as high bulk resistance and surface resistance, high dielectric breakdown strength, low moisture absorption and air permeability etc. The organic-fluorine electret powder TF11 dedicated to melt-blowing cloth has extremely high anti-static capacity with uniform micropores, which can increase the electrostatic adsorption capacity of PP and extend the time efficiency for storage of electric charge for 1 year efficiently. It is applicable to the melt-blowing cloth with a filtering efficiency of 95 or 99. Dosage and use methods The filtering efficiency can be remarkably improved only by adding 0.05-0.1% organic-fluorine electret powder TF11 in the melt-blowing cloth, to extend the storage time of electric charge. Electret masterbatch can be obtained through compounding of TF11 and the melting index PP. The dosage into masterbatch is 5-10% and organic-fluorine electret powder can be added directly during production of those with a melting index of 1,500 through masterbatch.