Abstract: High-rise buildings, characterized by low damping and exposure to multiple vibration excitation sources, face a widespread risk of abnormal vibrations. Identifying the sources of these vibrations therefore requires accurate and reliable localization techniques. Existing algorithms are not suitable for abnormal vibration scenarios in high-rise buildings under harmonic excitation. To address this gap, this study proposes a harmonic vibration source localization algorithm based on a multi-degree-of-freedom flexural shear model, designed to locate abnormal sources with specific frequencies in high-rise structures. The effectiveness of the proposed method is validated through a case study of a 77.7-meter-high reinforced concrete frame-shear wall structure.