The infrared spectral and thermal imaging experiments on infrared attenuation factors of foam were carried out. The infrared spectral characteristics of solution determine the absorption peaks, with a stronger absorption for a higher content. The foam structure is an important factor of attenuation, the transmission intensity decreases by the times of transmission through foam interfaces, and the smaller bubble diameter it is, the less dosage is used with the same shield effect. Once the bubble diameter is much larger than radiation wavelength, the transmissivity will depend less on the sizes of beam. Temperature rising can increase the infrared absorption intensity in some extent. The grade of impact factors declines in the sequence of foam structure, spectral characteristics, refractive index of inner gas, bubble diameter, and temperature.