Based on the theory of the atmosphere delamination,the characteristics of the near space′ environment have been analyzed，at the same time，the Beer law and the model of the Markov are respectively used to calculate and emulate the attenuation and the turbulence in the propagation of laser beam through the near space.It has been proved that the absorbtion of the O3,the scattering of the aerosol and the rayleigh scattering of the upper air molecules are the main factors to the attenuation of the laser，the laser in 30km high altitude has been hardly influenced by the turbulence,and the common-used 1.06μm′s irradiance scintillation is less than the 10.6μm laser and is more suitable for transmiting in the near space.