To clarify the causes of haze formation during blueberry wine storage and improve product quality, the morphology of haze was analyzed using scanning electron microscopy and its basic components were determined using Fourier-transform infrared spectroscopy, chemical analysis, high-performance liquid chromatography, and high-performance liquid chromatographytandem mass spectrometry. The study was focused on the amino acid composition, protein classification, and qualitative and quantitative characterization of the polyphenols and organic acids. The results showed that blueberry wine haze exhibited an irregular, layered stacking structure with smooth edges. The principal components were polyphenols, the concentration of which (640.98 mg•g-1) significantly exceeded those of the polysaccharides (322.92 mg•g-1), proteins (44.59 mg•g-1), and anthocyanins (7.46 mg•g-1). Glutamic acid (18.06%), glycine (11.28%), proline (7.75%), and serine (7.51%) were identified as the primary amino acids, whereas the proteins were determined to have originated predominantly from Saccharomyces cerevisiae. Fiftythree compounds were isolated and qualitatively identified as follows: 12 phenolic acids and derivatives, 15 flavonoids and derivatives, seven other phenolics, ten anthocyanins, and nine organic acids. Quantitative analysis revealed syringic acid (19 205.17 μg•g-1), epicatechin (31.12 μg•g-1), and fumaric acid (195.33 μg•g-1) as the predominant phenolic acid, flavonoid, and organic acid, respectively. This study systemically elucidated for the first time that blueberry wine haze is dominated by polyphenols, while also clarifying its complex compound composition and contents of key components, thus providing an important theoretical basis for controlling its formation during wine storage.