This study aimed to investigate the influence of natural fermentation on the quality characteristics of Cabernet Sauvignon wines produced at the Helan Mountain east foothill during different periods. Two different wineries were selected， and commercial brewing yeast was used as a control group to compare the effects of natural fermentation on the physical and chemical parameters. The analysis of aroma compounds was performed using headspace solid phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME/GC-MS). Sensory evaluations were conducted to assess the wine's sensory characteristics after fermentation. The results demonstrated that natural fermentation significantly affected the physical and chemical composition of the final Cabernet Sauvignon wines. Parameters such as total acid (5.67， 6.67 g/L)， pH (3.52， 3.37)， glycerol (12.53， 12.79 g/L)， total phenol (1 871.01， 1 614.33 mg/L)， and anthocyanin content exhibited (363.31， 440.57 mg/L) significant variations (P<0.05). Throughout the fermentation process， total acids and polyphenols gradually increased， while glycerol and anthocyanin content initially increased and then decreased. pH values showed an initial decrease followed by an increase. Aroma analysis revealed that several aroma compounds， including n-propanol (631 944.22， 480 893.41 μg/L)， 3-methyl-1-pentyl alcohol (204.61， 147.07 μg/L)， n-caproic acid (2 297.09， 3 054.19 μg/L)， trans-3-hexenol (24.21， 31.43 μg/L)， and 4-terpenol(4.65， 6.39 μg/L)， were significantly higher in naturally fermented Cabernet Sauvignon wines compared to the control group (P<0.05). Total aroma (1 495 527.85， 1 410 009.04 μg/L)， esters (70 686.36， 135 191.45 μg/L)， higher alcohols (1 373 156.7， 1 219 543.05 μg/L)， fatty acids (50 933.23， 53 754.49 μg/L) showed an increasing trend with fermentation. The content of aldehydes and ketones (566.51， 1 331.15 μg/L) first increased and then decreased， whereas the content of isoprene and other substances remained relatively stable. Sensory evaluation indicated that the overall rating of naturally fermented wines was slightly higher than that of inoculated fermentation. Odor Activity Value (OAV) analysis and principal component analysis (PCA) revealed a positive correlation between natural fermentation and ester compounds among 29 typical aroma substances. Pearson correlation analysis showed that natural fermentation was positively correlated with total sugars， total acids， total phenols， esters， higher alcohols， and isoprene substances， with a significant positive correlation observed with total acids (P<0.05). Conversely， it was negatively correlated with pH， volatile acids， glycerol， anthocyanins， and fatty acids. In conclusion， natural fermentation significantly influenced the physical and chemical parameters and aroma compounds of Cabernet Sauvignon wines produced at the eastern foot of Helan Mountain. Natural fermentation resulted in wines with superior flavor quality compared to inoculated fermentation.