Abstract: An identification method of coal and rock interface based on principal component analysis was proposed, and principle of principal component analysis and identification process was described in details. The method uses multiple sensors to monitor parameters simultaneously of shearer when the shearer is cutting coal, and does real-time principal component analysis of the parameters. The coal and mine interface is identified by capturing exceptions in cutting course according to statistics of HotellingT2 and SPE which were established with main meta information. The practical application showed that the method can identify coal and rock interface rapidly and accurately.