Abstract: A further improvement of the interpretation accuracy of transient electromagnetic data on the ground has been the focus of this method. A time-depth conversion method is established by using the concepts of double journey time and average velocity based on the diffusion theory of transient electromagnetic smoke ring effect in order to over- come the problem of depth reversal which may occur when transient electromagnetic exploration depth is calculated by simple empirical formula. With the depth of No. 9 coal seam obtained from three-dimensional seismic data as the cor- rection standard of electrical marker layer,the apparent resistivity differential extremum points are used to accurately identify electrical marker layer,and the depth correction coefficient K of corresponding transient electromagnetic meas- uring points is calculated by ratio method. Then the K value of any point in the measuring area is obtained by interpo- lation method,which provides a basis for the accurate processing of data. Based on the resistivity log data from bore- hole ZKB1-1 and ZK201 of Baozi Mine,the forward theoretical model is established,and the transient electromagnetic response is calculated. The results show that they are basically consistent and can accurately identify the electrical in-terface. Taking 256-line and 344-line as examples, the identification effect of the electrical marker layer was ex-plained,the depth correction coefficient of the whole Baozi Mine area was calculated,the data in the area was fine pro-cessed,and the area of low resistance anomaly at the Ordovician limestone tops of the working area was determined. According to the surface runoff and the apparent resistivity in whole area,the existence and location of the water diver-sion channel were determined. The resistivity was regarded as the basic parameter,the stratigraphic hydrogenicity water in the area were analyzed and evaluated. Finally,the drilling verification shows that the accuracy error of this method is less than 5% ,which achieves the fine interpretation of ground TEM data.