Abstract: This paper examines the impact of underground coal mining on ground vibrations, using a large mine in northern Anhui as a case study. By continuously collecting monitoring data from the Global Navigation Satellite System（GNSS）, the research investigates the effects of coal mining beneath thick loose layers on ground vibrations and subsidence. The FLAC^3D numerical simulation software is employed to model the geological data and simulate the vibration propagation process during underground mining operations. The results indicate that as vibration waves propagate upward from the top of the coal seam tunnel through the loose layers, the vibration energy gradually attenuates, particularly showing significant attenuation in thick clay layers. Subsequently, Variational Mode Decomposition（VMD） and spectral analysis are utilized to process and analyze the ground vibration data, revealing the frequency characteristics of underground mechanical mining vibrations after passing through the loose layers, as well as the attenuation patterns of these vibrations. Additionally, an analysis of subsidence data from monitoring stations reveals a trend of initial increase followed by a decrease, with 91% of the total subsidence occurring during the active period. The study also examines the influencing factors and the duration of the vibration impacts. The findings provide scientific evidence for the safe management and environmental protection of coal mining activities.