Abstract: To address the issues of identifying and locating characteristic wavelengths of track irregularities and effectively determining the geometric deformation of deteriorating track structures, this study proposes a track geometric deformation monitoring algorithm based on the scale-wavelet energy spectrum. The algorithm leverages the significant increase in energy spectrum values at corresponding wavelet scales for irregular signals of different wavelengths, combined with the principle of small probability events of normal random variables, to achieve precise monitoring of track geometric deformation. Through computational analysis of measured data, the effectiveness of the algorithm in identifying, locating, controlling, and monitoring different wavelength (segment) irregularities has been verified. The research results provide reliable technical support for the maintenance and repair work of railway engineering departments as well as the vibration control of the vehicle/track system, demonstrating significant engineering application value.