Along with the modern industry and the science and technology rapid development, the modern equipment structure is more and more complex, the equipment movement security and the reliability obtained society's widespread attention, in which neural network technology by its may the real-time movement, antijamming ability, the diagnosis rate of accuracy higher characteristic, is holding the important status in the intelligent breakdown diagnosis the practical application, 80%-90% artificial neural networks model is uses the BP network or its change form, so long as theoretically the BP neural network has enough many implicit stratas and the hidden point, may realize the complex mapping relations, moreover the BP algorithm is the overall situation approximate algorithm, has well exudes ability. First the paper has carried on the summary in the consult massive correlation literature foundation to the breakdown diagnosis method, specially summarized and has analyzed based on the knowledge breakdown diagnosis technology application scope and the trend of to has conducted the fundamental research based on the BP neural network breakdown diagnosis method, finally has carried on the failure detection and the breakdown diagnosis simulation experiment take the TE process as the example studies, has confirmed the BP neural network validity.