<p>This study investigated the performance characterization and coating mechanism of polyvinyl alcohol (PVA)-coated nanoaluminium (nAl) powder (nAl@PVA) using various techniques, including Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy, dynamic light scattering, scanning electron microscopy, transmission electron microscopy and thermogravimetric analysis–differential scanning calorimetry. It also explored the interaction mechanisms between PVA and nAl through density functional theory (DFT)-based adsorption energy calculations, Mayer bond order analysis, electron localisation function analysis and projected density of states analysis. The results indicated that nAl@PVA exhibited nanoscale particle size and a narrow particle-size distribution, albeit with slight agglomeration. A distinct core–shell structure was observed, confirming the effective coating of nAl by PVA. The intense Al–OH peak in the FTIR spectrum suggested a notable interaction between the hydroxyl groups of PVA and nAl. According to the DFT calculations, this interaction was mainly driven by the interaction between Al and O atoms, which was dominated by the overlap of O 2pz and O 2py orbitals with the Al 3s orbital.</p>