Water-jet cutting machine is one of the high-tech products setting of ultra-high pressure technology, numerical control technology, computer application technology as a whole, make use of the kinetic energy of abrasive water-jet cutting of various materials to achieve the purpose of cutting. It has advantages such as no chemical changes, no heat distortion, thin cutting gap, high accuracy, aspect bright and clean and clean pollution-free. Aiming at the problem of many kinds of fault and so difficult to obtain a large number of fault data samples on pressurization system of water-jet cutting machine. A new method of fault diagnose is proposed for pressurization system of water-jet cutting machine based on SVM —one to one classification, this method was used for building a multi-fault classifier on the training set. Then it is applied to fault diagnosis of pressurization system of four-axe linkage water-jet cutting machine, and the results show that it has high efficiency. And do not need to preprocess of the original signal to satisfy the need of on line diagnosis.