At present

the design of tower foundation for transmission line is plotted on two-dimensional（2D） drawings

but this method does not fully consider the impact of topography and surrounding environment on the scheme

and there also exists deviations in the calculation of quantities. The application of threedimensional (3D) design technology in transmission line provides a new method for tower foundation design. The work contents of tower foundation design are analyzed

and a new tower foundation design method based on 3D model is proposed. Firstly

after comparing the advantages and disadvantages of 2D and 3D design

it is confirmed that through the establishment of virtual 3D small scene and 3D large scene of tower location

the evaluation and optimization of tower foundation design scheme can be more intuitive. And then based on the idea of parametric modeling

the model types included in tower foundation design are defined and its modeling rules are analyzed. Finally

an actual tower location in the project is chosen to build a 3D digital model by using 3D modeling program of tower foundation and GIS platform. The rationality of tower foundation design scheme is intuitively evaluated. Compared with the 2D design

the proposed method can improve the accuracy obviously.