The ground surface is not an ideal conductor of a homogeneous medium. The traditional one-dimensional atmospheric electric field component cannot accurately locate the thunderstorm cloud. When the three-dimensional field intensity component of the atmospheric electric field is used to locate the thunderstorm cloud, the field strength of the electric field and the altitude angle of the thunderstorm cloud are often measured. The electric field will be affected by the dielectric constant of the ground and air, resulting in positioning errors. In order to solve the problem of low positioning accuracy of thunderstorm clouds, this paper analyzes the sensitive characteristics of the three-dimensional atmospheric electric field to the relative permittivity of the surface, combined with the mirror image method, and establishes a thunderstorm cloud positioning model using the principles of electric field distribution in the air and the charge structure of thunderstorm clouds. Analyze the relationship between the atmospheric electric field strength, altitude angle and the relative permittivity of the environment. The experimental results show that the greater the relative permittivity of the surface, the greater the measured electric field horizontal component and the height angle of the thunderstorm cloud. The correlation coefficient between the relative permittivity of the surface and the horizontal component of the atmospheric electric field is -9. 5, showing a negative correlation. Therefore, to obtain the accurate height and azimuth of the thunderstorm cloud, the relative permittivity of the ground surface must be corrected in real time.