Abstract: With the continuous development of coal resources, the upper group of coal in some coal mines has been mined out, and it is urgent to solve the detection problem of the lower group of coal. Affected by the goaf formed by the upper group of coal, the seismic energy absorption and scattering attenuation of the lower group of coal are significant, and the signal-to-noise ratio of the data is low. The detection of the lower group of coal under the goaf by 3D seismic exploration is still in the exploration stage. In this paper, the 3D seismic exploration project of the lower group coal in the goaf of Dongpang Coal Mine of Jizhong Energy Group is discussed. The detection effect of lower group coal beneath goafs of different ages is compared and analyzed by using the technologies of "2W1H"(Wide-band, Wide azimuth and High-density) acquisition, high-precision data processing and attribute body interpretation. The results show that the seismic information on the lower group of coal can be obtained by using the "2W1H" acquisition technology. The technologies of amplitude compensation and seismic frequency extension make the reflection wave group of No.9 coal seam plenty and continuous. When the goafs'age is more than 10 years, the broken strata are compacted and relatively stable, and the reflection wave of the lower group of coal is easy to track. When the goafs'age is less than 10 years, the broken strata are not compacted, leading to weak and disordered reflected wave energy of the lower group of coal. This knowledge has a certain guiding significance for the detection of the lower group of coal in similar coal mines.