On the basis of the existing characteristic industry selection research results and the related economic theory, the standard of county characteristic industry identification is put forward,and the characteristic industry identification index system is constructed from three aspects of industrial development level, industrial characteristic standard and industrial comparative advantage, then the county characteristic industry identification model is established. Based on the analysis of location entropy, a preliminary selection of characteristic industries in Xiuning County of Anhui province was made, and the principal component analysis method was used for further selection. Through empirical analysis,it will provide certain bases for the cultivation and development of county characteristic industries.