Abstract: With the increasing of mining depth, a series of new problems will be encountered. According to the characteristics that many researching objects in mining engineering have property of"the connotation is explicit, the extension is vague", and the fuzzy nature of the decision-maker in the problem formulation process, in this article, some fuzzy concepts of mining engineering some basic methods and definitions of fuzzy mathematics are discussed simply at the first time. Then, an expert system of which based on fuzzy mathematics is proposed. Some basic methods of fuzzy mathematics are referred to the device of the database and logic machine. At the same time, the basic theory of the new system is introduced. The main differences with some others expert systems are also expounded. The new system includes five parts. " New Orleans Methods"is referred to the device of database. Finally, the application of the new system in mining engineering is studied preliminarily. Some utility conclusions are given.