In order to make full use of the scarce spectrum resources, and solve the "black out" problem of near space communication, a nonuniform plasma sheath is built by selecting a Gauss distribution model combined with the millimeter wave atmospheric window with high transmittance in the atmosphere to study the influence on attenuation of millimeter wave atmosphere window in the process of transmittance in the atmosphere on account of frequency changes subjected to the collision between attack angles and plasma sheath on condition that there are additional different intensity magnetic fields and on no condition. The simulation results show that the magnetic field with different intensities added on the plasma sheath can change the attenuation value of the millimeter wave atmospheric window, but can not change the transmission law of the millimeter wave atmospheric window. The external magnetic field does not necessarily improve the transmission performance of the millimeter wave atmospheric window, but also needs to consider the resonance frequency of the plasma sheath and the millimeter wave window. The results provide effective theoretical data support for the establishment of near space communication platform.