A visualized analysis system of leak current fault transmission graph is developed. Its functions, program structure and programming principle are described.The system is composed of fault diagnosing module and man machine exchanging module, which make the generation and analysis of leak current fault transmission graph for lauch vehicle controlling system simple and visualized. The system could automatically recognize the picture of transmission and analyze both qualitatively and quantitatively only by drawing it on the monitor by the mouse. Finally an example is given, where a satisfying result is acquired via drawing inputting method which is totally new and expanding-complementing the fault tree alglorithm.