The technology of in-seam seismic exploration can effectively detect small faults, collapse columns and other geological anomalies in coal seam, and is obviously superior to other underground exploration methods in detection accuracy and distance. As a basic in-seam seismic detection method, transmission method has the advantages of simple and flexible, large detection range and high accuracy. In this paper, the transmission in-seam wave method is used to detect the fault structure in the actual coal mine working face, and the transmission in-seam wave data are carefully processed through the key technologies such as filtering, dispersion analysis, wave field and velocity analysis, energy analysis and transmission CT imaging, so as to obtain the accurate transmission in-seam wave imaging profile. According to the characteristics that the energy of the in-seam wave will decrease sharply when it is blocked by faults in coal seam or when the coal seam is broken, 12 reliable faults are explained by using the energy CT profile of the transmission in-seam wave and combining with the actual disclosure. Through the test of the transmission in-seam wave exploration method in coal seam face, the validity of the transmission in-seam wave method and its practical value in the detection of coal faults and other structures are verified.