The invention relates to a structural abnormality detection method based on consistent data replacement under incomplete data, which comprises the following steps: firstly, carrying out collection on a structural response by utilizing a plurality of sensors, wherein certain sensors become invalid, thereby, obtaining response signals containing the incomplete data; then, carrying out denoising processing on all the collected signals; subsequently, carrying out complete processing on the incomplete data in the signals by utilizing a consistent data replacement method; and finally, decomposing the completely processed data by utilizing a small wave to realize structural abnormality detection. The method is capable of well processing multiple-degree of freedom, non-free vibration, nonlinear, unsteady and incomplete response signals, can be used for signal processing in the field of civil engineering, aerospace, automatic control, mechanical engineering, bridge engineering, hydraulic engineering and the like, and has the characteristics of improving the anti-jamming capability of the data and improving the structural abnormality detection accuracy under the incomplete data.