Abstract: In recent years, advancements in geophysical instruments, equipment, and sensitivity have enabled the widespread application of micro-tremor array detection, a natural source geophysical method, in engineering exploration and shallow geological surveys. In this study, we aimed to classify the bedrock relief interface of a pumped storage project site, determine the thickness of its overlying layer, and identify hidden fault structures in the working area. According to the real working conditions at the site, micro-tremor array detection technology featuring strong anti-interference ability and high efficiency and speed was selected. The theoretical simulation results showed that the dispersion curves obtained using a linear array and triangular nested array were consistent with the theoretically calculated values. Therefore, a linear array method was adopted to detect two survey lines arranged in the working area. A data collection method was adopted to obtain abundant geological information in the shallow layer to accomplish high-precision detection of the shallow surface. Based on the SPAC method, the phase–velocity dispersion curves of the fundamental Rayleigh waves were extracted from each measurement point of the two survey lines. The S-wave velocity structural profiles of the two survey lines were obtained via inversion interpolation. The detection results indicated that the thickness of the covering layer in the working area was basically consistent with the verification results of the drilling data, and no shallow geological bodies were found. This provides reliable shallow geological information for the construction of pumped storage projects.