Visual measurement methods can be adopted to directly obtain vibration images with high spatial resolution and time synchronization

and have broad application prospects in synchronous measurement of vibration images and mechanical condition evaluation of oil-immersed reactors. Due to the fact that the vibration amplitude of power reactors is only at the micron level

existing 3D digital image correlation (3D-DIC) techniques suffer from limited accuracy in identifying such small-scale motions. To address this issue

this paper proposes a vibration measurement method for oil-immersed reactors based on visual enhancement by integrating vision phase motion magnification (VPMM) with 3D-DIC. First

the effectiveness of VPMM in extracting single-frequency micro-vibration signals is validated

showing a deviation of less than 0.7  μm between the measured amplitude and the actual value. Meanwhile

the method demonstrates higher spatial resolution and temporal synchronization. Second

the accuracy of the visual-enhancement-based method in capturing multi-frequency micro-vibration signals of the reactor is verified. Compared with traditional 3D-DIC

the combined VPMM+3D-DIC approach achieves higher fidelity in reconstructing micro-vibration signals and their spectral content. Finally

the operational deflection shape (ODS) of the reactor tank under different excitation voltages and mechanical conditions are measured. The results show that the ODS remains stable under voltage fluctuations (SSIM>0.85) and is sensitive to loosening defects (SSIM<0.09). Overall

the proposed method achieves high-precision vibration response measurements

and the extracted fundamental mode shapes not only reflect the stability under voltage variations but also exhibit high sensitivity to mechanical conditions.