Based on the current status of fault record analysis software for power system in China and the tendency of computer technology development， a 3-D method for fault analysis in electric power system is proposed. The advantage of 3-D method for fault analysis is discussed， and the technology of OpenGL is introduced. By taking impedance locus as an example， an algorithm of generating 3-D vector data and other graphs of 3-D analysis modules for fault analysis in power system are given. The real-time interactive technology and data interface design of the 3-D modules are discussed. The application prospect of the 3-D analysis method for the fault analysis in the power system is summarized and pointed out.