This study aims to figure out the structure of the microbial community in traditional sourdough and the different flavor components of Chinese steamed bread(CSB) made with it. The sourdough samples were selected from Shanxi, Henan and Shandong provinces. The microbial community composition of the sourdoughs was analyzed by a culture-dependent method and high-throughput sequencing, and the flavor compounds of the steamed breads were determined by the solid-phase micro extraction (SPME) method coupled with gas chromatography/mass spectroscopy (GC/MS). The results showed that: in the 28 samples collected, the pH ranged from 3.50 to 4.91, and the total titratable acid (TTA) values ranged from 2.50 to 7.80 mL of NaOH (1 M), while the total number of lactic acid bacteria (LAB) colonies ranged from 10^4 to 10^7 CFU/mL. Lactobacillus, Lactococcus, and Weissella were the dominant genera, as determined by pyrosequencing. A total of 180 LAB strains were isolated and identified using the 16S rRNA gene; the results indicate that Lactobacillus plantarum, Lactobacillus fermentum, and Weissella confusa were isolated with a relatively high frequency. By GC/MS, a total of 24 volatile compounds were detected, including hydrocarbons, aromatic compounds, alcohols, esters, aldehydes, acids, etc. Benzeneethanol and benzaldehyde were abundant in all five samples detected, while benzene-propoxyethyl was not detected in the control group.The flavor compounds contained in sourdough fermented CSBs, both in terms of quantity and concentration, are higher than those in yeast-fermented CSBs. This study provides a useful base for further exploring the deep connections between microbial communities and food flavors.