Abstract: In order to detect the structural development of the coal seam in the working face,the in-seam wave velocity tomograpgy technology was used for CT imaging of the coal seam in the working face.First,the physical parameters of the coal seam in the working face were inverted according to the velocity of each in-seam wave ray,and then the CT imaging of the in-seam wave velocity of the coal seam in the working face was performed by the improved Algebraic Reconstruction Technique (ART).The application showed that the predicted results of the geologic structutrs in the working face agreed well with the actual situation.