Based on the mine transient electromagnetic detection theory in combination with underground transient electromagnetic detection test, the authors studied the roadway influence and detection method of coalface detection by using mine transient electromagnetic method and put forward the "intersection method"for mine transient electromagnetic coalface detection, i.e., in downhole practical exploration, two adits should be dug for coalface. This method was tested in a coal mine in Luliang of Shanxi Province, and the result shows that the "intersection method" can make more accurate detection, improve the detection accuracy and reduce the drilling workload. This is a reliable method for mine transient electromagnetic detection of coalface. It is thus held that the use of this method should be promoted in the coal mine.