Based on the laser signal's emission, propagation and detection during the in-door laser simulation, the effects of the aerosol's Mie scattering is provided for the 1.06μm laser signals. By the construction of the models of the indoor aerosol's scattering, the laser designator's propagation simulation and calculation are carried out. Finally, the discussions related to the arrangement and the methods to reduce the effects of the scattering are delivered in terms of the analysis of and verification by practical measure data.