Study aerodisperse flows laser methods is an effective means of obtaining knowledge. Information content of this knowledge can be greatly enhanced by the simultaneous sounding of streams at several wavelengths. In this case, there is a need to improve the accuracy of joint measurements at selected wavelengths of laser light. The authors constructed a system for the study of flows aerodisperse laser techniques at three different wavelengths. allows simultaneous measurement of scattering and attenuation characteristics of the laser radiation by aerosol particles. Measurement accuracy is enhanced by the fact that all the beams pass the same optical path in the flow of radiation at all wavelengths adopted for general photodetectors and all measurements at each wavelength are carried out simultaneously.