To address safety and efficiency concerns related to installing large equipment, such as gantry cranes, beneath a 500 kV extra-high-voltage transmission line during urban subway construction, Ansys finite element analysis software was used to simulate the electric field distribution around the transmission line and accurately determine the safe construction height at the site. On this basis, key factors, including foundation bearing capacity, truck crane lifting capacity, forces in slings and guy ropes, and ground anchor bearing capacity, were calculated and analyzed in detail. The results verified the rationality of the equipment selection, and a safe and feasible construction plan was developed. The plan effectively ensures construction safety and improves construction efficiency. It provides reliable technical support for subway station construction beneath 500 kV extra-high-voltage transmission lines, as well as an important reference and practical guidance for large-equipment hoisting operations under similar conditions.