Abstract: Coal seam gas production potential of indigenous microorganisms could be stimulated by normally adding nutrients (primarily organic nitrogen sources). However, the addition of nutrients to four bituminous coals with different volatiles (PS (Panji San Mine) 37.50%, ZJ (Zhangji Mine) 33.02%, QN (Qinan Mine) 25.19%, ZZ (Zhuzhuang Mine) 14.01%) did not result in significant methane production. After adding 1 mL each of Clostridium perfringens, and Bacillus subtilis subsp to all samples on the 30^th day, the changes in methane production potential of various bituminous coals were analyzed. Evolution process of microbial composition and structure of archaea and bacteria during methane production was investigated. Meanwhile, significant differential metabolite change pattern for the degradation of carbon containing compounds in coal affected by Bacillus excitation was constructed based on untargeted metabolomics analysis. Results show that methane production increased, reaching a peak on the 54^th day with the following values: PS (145.222 μmol/g), ZJ (127.556 μmol/g), QN (116.314 μmol/g), ZZ (84.105 μmol/g). From T1 to T2 (T1 was culturing for 30 days with only adding nutrients, while T2 was culturing for 30 days after adding degrading bacteria). The Shannon diversity index of archaea in each culturing group decreased significantly, with methanogenic genera such as Methanosarcina (39.74%−87.48%), Methanoculleus (0.84%−18.72%), and Methanomassiliicoccus (2.44%−12.49%) becoming the dominant archaea, and their contents increased. In contrast, the Shannon diversity index of bacteria rose (PS: from (4.17±0.19) to (7.35±0.11), ZJ: from (4.72±0.17) to (7.35±0.07), QN: from (4.48±0.21) to (6.29±0.10), ZZ: from (5.58±0.07) to (6.57±0.07)). Based on KEGG metabolic pathways and untargeted metabolomics analysis, the relative abundance of methanogenic metabolic functional genes in the four sample groups significantly increased (PS: from 8.79% to 35.61%, ZJ: from 5.56% to 31.67%, QN: from 7.54% to 31.35%, ZZ: from 8.45% to 27.23%), with a higher relative abundance of hydrogenotrophic (E23.1.101, E1.2.7.12) and methylotrophic (E2.1.1.248) pathways. The differential metabolites primarily included aromatic rings, heterocycles, and fatty compound. The addition of functional bacteria may have accelerated the degradation of these three compounds, providing utilizable substrates for methanogenic archaea and enhancing the gas production potential of microorganisms in bituminous coal.