Laser measurement technology is widely used in antenna main reflector and subreflector deformation or pose measurement. Based on the laser measurement technology, atmospheric turbulence caused by the atmospheric characteristics or the convergence effect of the antenna itself will affect the refractive index disturbance during laser propagation, which affects the accuracy of the laser measurement of the antenna deformation or pose. In order to solve the problem of laser atmospheric propagation deflection caused by atmospheric turbulence on the near-ground of a large-aperture antenna, firstly, this paper decomposes the laser atmospheric propagation path into multiple isotropic air layers, calculates the atmospheric refractive index of each air layer, obtains the atmospheric refractive index of the whole laser propagation path through curve fitting methods, and then assesses the laser deflection. Secondly, the turbulence intensity under sunny daytime and cloudy nighttime are evaluated, the laser spot position deviation is compared and analyzed, and the matching relationship among turbulence intensity, theoretical deviation of the laser spots, and actual spot deviation is obtained. Finally, the deflection of laser atmospheric propagation is fitted and calculated by measuring environmental data matched to the actual experimental data of the Nanshan 26m radio telescope antenna, which verifies the effectiveness and feasibility of the proposed method. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.