The quality inspection of concrete structures is a key link to ensure project safety and extend service life. Traditional quality inspection methods, such as ground penetrating radar (GPR), are often interfered by steel mesh when detecting internal defects of concrete, resulting in inaccurate inspection results. The presence of steel mesh will have a shielding effect on electromagnetic waves, making it challenging for GPR to detect concrete quality defects behind the steel mesh. In response to the above problems, a detection method based on elastic wave frequency eigenvalues has emerged. Elastic waves have good penetration ability and high sensitivity, especially when detecting the internal structure of concrete, they can provide detailed information. This paper introduces a concrete void area detection method based on elastic wave frequency eigenvalues ​​that is not affected by steel mesh shielding. This method can achieve multi-parameter positioning of lining voids by comprehensively analyzing the time domain waveform characteristics and instantaneous amplitude characteristics. As a beneficial supplement to the ground penetrating radar method, this method provides a new technical means for concrete structure quality inspection.