The entire fermentation process of traditional Chinese broad bean paste with chili comprises three individual stages: Tianbanzi, chili pei, and paste fermentation (Tianbanzi-chili pei mixture). Three stages share average 77.53% of all bacteria (89 genera), indicating that the similar environment leads to the similar bacterial communities. One, one, and three genera are exclusive to Tianbanzi, chili pei, and paste stages, respectively, due to the special physical and chemical properties for each stage. Total acidity, pH, and NaCl are important endogenous factors that promote the succession of bacterial communities. According to the dynamics of organic acids, reducing sugars, amino acids, and volatile compounds, 60-, 210-, and 180-day are considered the best fermentation periods for Tianbanzi, chili pei, and paste, respectively, to balance time cost and product quality. Three (Tetragenococcus, Lactobacillus, and Pseudomonas), four (Tetragenococcus, Lactobacillus, Bacillus, and Pseudomonas), and five (Tetragenococcus, Lactobacillus, Bacillus, Pseudomonas, and Pediococcus) genera are considered the core functional bacteria of Tianbanzi, chili pei, and paste fermentation, respectively.