Abstract: In order to study the effect of TEM on the detection of mine tunnels in small coal bearing basin inclined coal seam, mine tunnels of a syncline basin in Yunnan Province is taken as the research object, and research is carried out from numerical simulation and field measurement. First of all, the inclined coal seam electricity section model is set up based on geological conditions of the study area, one dimensional forward modeling and resistivity calculation are used to demonstrate the feasibility of the theory; Secondly, TEM network is arranged according to the conditions of the field, optimum working parameters are set up according to the simulation results, field data with high signal-to-noise ratio are collected, resistivity anomaly is identified according to take coal bearing section as electrical marker layer, and distribution and geological causes of mine tunnels are analyzed and deduced. Finally, the inferred mine tunnels are exposed by advance drilling undermine. The results show that TEM is adapted to the change of geoelectric section structure by inclined strata, the fluctuation of the inclined coal seam in the coal bearing basin, location and scope of mine tunnels are clearly identified by the detection results, and TEM is suitable for application in Neogene coal bearing basin inclined coal seam.