Workers in the activities under high-voltage lines are exposed to the influence of the electric field of these lines, which may cause, in some cases, death as a result of some serious accidents such as the collapse of the towers and the occurrence of line to ground faults. In some densely populated countries, people may live near the right-of-way (ROW) of extra high-voltage transmission lines (EHVTLs), which may cause, as a result of the high electric field, health problems, for this reason, some researchers have pointed out the possible relationship between exposure to electric and magnetic fields on the one hand and the appearance of some diseases, especially in children, on the other hand. The aim of this article is to suggest a way to reduce the electric field in the place where people are found by using metal grids at safe distances from the EHVTLs. In this article, the electric field is calculated in the event that these grids are isolated or grounded. A comparison between the electric field without the use of shielding grids and with using these grids when they are isolated and earthed is carried out. The effect of changing the location of the shielding grids on the electric field values is examined. It is illustrated from this study that the peak value of the electric field intensity is mitigated to be 16.66% of its value before shielding, which proved the method's effectiveness in reducing the intensity of the electric field. The effect of an isolated shielding grid is to shift the electric field curve to be more flat. The installation of the earthed grids beside and parallel to the lines has a significant influence on the mitigation of the electric field under the EHVTL.