The ferrography technology is an effective way to diagnose the wear faults of mechanical equipment. This paper has introduced the current application of traditional ferrography technology. It is difficult to realize the online monitoring of oil and the automatic recognition of the abrasive grains by the traditional iron ferrography technology. The intelligent development of the iron ferrography technology makes the automatic recognition of the abrasive grains be realized. Then it has summarized the research and application of intelligent ferrography technology from such four aspects as intelligent online ferrograph image theory, BP neural network, support vector machine and fuzzy set theory. Those researches have important guiding significance for the further research of the ferrography intelligent identification system.