Abstract: To investigate the effect of fermentation with Eurotium cristatum on the flavor characteristics of Guizhou white tea, this study utilized second-grade white tea from Guizhou as the raw material. Scattered tea was subjected to fermentation with Eurotium cristatum, and the flavor characteristics of traditional white tea (WT) and white tea fermented with Eurotium cristatum (ECWT) were analyzed using a combination of sensory evaluation, high-performance liquid chromatography (HPLC), headspace solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS), flavor activity value (TAV), odor activity value (OAV), and multivariate statistical methods. The results indicated a significant alteration in the organoleptic quality of WT following fermentation to produce ECWT. Specifically, the color of the tea deepened, while freshness diminished; conversely, sweetness and smoothness were enhanced. The floral aroma was notably reduced, whereas fungal flower notes became more pronounced. Upon fermentation with Eurotium cristatum, a significant variation in the concentrations of various bioactive compounds was observed in the Eurotium cristatum-fermented tea (ECWT) as compared to the traditional white tea (WT). Specifically, the levels of theobromine, EGCG (epigallocatechin gallate), GCG (gallocatechin gallate), ECG (epicatechin gallate), theanine, glutamic acid, aspartic acid, alanine, serine, valine, leucine, isoleucine, tyrosine, phenylalanine, histidine, lysine, and proline were markedly decreased by 41.68%, 81.12%, 52.48%, 68.22%, 93.07%, 83.64%, 50.00%, 91.67%, 96.49%, 65.79%, 74.36%, 83.33%, 94.79%, 93.75%, 62.50%, 92.31%, and 76.09%, respectively (P<0.05). In contrast, the levels of serine, methionine, and cysteine in ECWT were significantly increased by 2100.00%, 36.25%, and 725.00%, respectively (P<0.05). Notably, the concentrations of caffeine, glycine, and arginine did not show any significant variation (P>0.05). Collectively, the total amino acid content in ECWT was found to be significantly reduced by 86.40% in comparison to traditional white tea (WT) (P<0.05). The key taste compounds of traditional white tea (WT) included caffeine, EGC (epigallocatechin), C (catechin), EC (epicatechin), EGCG (epigallocatechin gallate), GCG (gallocatechin gallate), ECG (epicatechin gallate), theanine, glutamic acid, tyrosine, and methionine. In contrast, the key taste compounds of Eurotium cristatum-fermented tea (ECWT) were caffeine, EGCG, GCG, ECG, theanine, methionine, and cysteine. A total of 74 aroma substances were detected in WT and ECWT, of which 62 were key differential aroma substances and 49 were detected in WT. This included 31 key aroma compounds and 17 essential aroma-causing ingredients. In the case of white tea fermented with Eurotium cristatum (ECWT), 55 aroma substances were identified, comprising 28 key aroma compounds and 16 critical aroma-causing ingredients. The flavor characteristics of white tea underwent significant changes following the fermentation of scattered tea with Eurotium cristatum. The findings of this research can provide valuable theoretical insights for optimizing fermentation processes and developing products derived from Eurotium cristatum scattered tea.