The forming pro cess and screening characteristics of red phosphorus smoke were elaborated. The mass extinction coefficients and granularity distribution of red phosphorus smoke to 10.6μm laser emission with two kinds of incident power were tested in a smoke to laser of chamber. The absorption efficiency factors, scattering efficiency factors and extinction efficiency factors of a single particle of red phosphorus smoke to laser of 10.6μm were calculated according to Mie scattering theory in far-infrared band. By the experiments, the average extinction coefficient of red phosphorus smoke to 0.552 W is 0.6027m^2/g and to 1.032 W is 0.5739 m^2/g. The average diameter of the smoke particles is 2.47 μm when the smoke formed 5 min. By the analysis, the extinction ability of red phosphorus smoke to 10.6μm laser emission depends upon the absorption effect. The mass extinction coefficient decreases while the smoke concentration increases. Under the same condition, the extinction coefficient of the smoke to 10.6μm laser emission will decrease when the power of incident laser emission increases or the air relative humidity decreases.