Abstract: The main characteristics of geo-engineering design is non-structure, non-parameter and non-standard, meanwhile, risk optimazing and feed back changeable. Only a formula and regular method used is not suitable to geo-engineering design. It must develop a non-structure tool that can automatically create object-oriented solution path following the geo-engineering characteristics. The basic contents of geo-engineering design are summarized, and the geometry-based and the AI-based, computer aided geo-engineering design of support system is discussed. A case-study illustrates that the computer-aided geo-engineering design of support system is applied to the geologic hazard controlling project of the Lianziya dangerous rockmass of the Three Gorges , the Yangtze River.