For choosing a material to interfere with IR and laser,the IR and 10.6μm laser transmissivity of micron-copper powders of different components were tested in the smoke chamber,when the concentration of the smoke reached 1.0 g·m-3,the transmissivity of 1~3μm,3~5μm and 8~14μm IR under 30%,and the transmissivity of 10.6μm laser under 20%,the attenuation ability of red copper powders,green and red copper powders and green copper powders to IR and 10.6μm laser increased gradually.At the same time,the interferential effect of the micron-copper powders to thermal imager were tested，when the concentration of the green copper powders reached 2.0 g·m-3,the thermal imager was completely defiladed.