Ningdong-Shandong ± 660 kV DC Power Transmission Pilot Project is the first DC transmission project of ± 660 kV voltage class in the world, which has important demonstrative meanings. In the project, the construction department of SG Corp. adheres to both technology innovation and management innovation, and creatively proposes a new idea of "three-dimensional digitalization transfer" (TDDT). This study has researched the work process and result of implementing TDDT. Meanwhile, a standardization document is developed on the basis of the project. Furthermore, the study summarizes experience of TDDT and also puts forward a proposal for the development direction and application future of TDDT. TDDT is an innovation of power grid project transfer approach and management, which has considerable popularization value and can better services for the grid design, construction, operation and maintenance.