The development of an intelligent fault testing equipment for electrical system of a mechanized bridge is accomplished based on embedded system. This equipment consists of USB communication interface, data acquisition unit, intelligent fault diagnosis as well as maintenance and management function together with embedded microprocessor MSP 430. It can carry out data acquisition and condition monitoring with multiple operating parameters, such as voltage, current, resistor, frequency as well as other operating state values. The fault testing and diagnosis are automatically performed by the application of measured data, user input observation results that are represented by logical value, and the detection results of other testing equipment. In addition, The graphical user interface facilitates users measurement and observation till to the location of the fault parts, and subsequently help users make maintenance solution and scheme. So far, the detecting precision meets the requirements of fault testing of electrical system. The equipment has also benefits of handy structure, lightweight, low consumption, large storage capacity, excellent expandability and intelligent inference capability. It provides engineering vehicles, for instance mechanized bridge, with proper and dedicated intelligent monitoring, diagnosis and testing equipment. Meanwhile the work presents an important technical method for the technical support of the various engineering equipment in time of war.