An adaptive Gaussian attenuation image defogging algorithm based on edge preservation is proposed to solve the problem when transmissivity is estimated under the local similarity assumption, the abrupt change edge of depth field often leads to the Halo effect .This method starts from the atmospheric scattering model and introduces the luminance of the sky, the estimation of scene transmissivity can be equivalent to the estimation of the luminance of the sky. The edge information is extracted by the edge detection operator to separate the edge region and the non-edge region. The adaptive Gaussian function is constructed by using the spatial proximity of the pixel points in the neighborhood to smooth and attenuation on the non-edge region, thereby obtaining the optimal effect. Through a large number of experiments to verify the proposed method, the results show that the restored image is smooth and the details are obvious. It can effectively eliminate the Halo effects at the abrupt changes of the depth field, and it also shows its advantages in the objective evaluation.