Using three-dimensional(3D) visualization technology to realize the management of transmission lines is a current developing direction on electric power information. However

the Earth is an irregular ellipsoid

which makes it hard to work out the coordinates in world space on the tower hanging point. Furthermore

it cannot truly describe the connecting condition between lines and tower hanging point. For these reasons

on the basis of analysis and research

we provide a hanging point calculating method that use the tower space of Google Earth as a starting point. The method is applied to the developed transmission line management system. With the characteristic of simple calculation

high precision

as well as having a real connection line and hanging point

etc. This method can meet the requirements of existing applications.