The knowledge about the association of lignocellulosic biomass-degrading microbes with lactic acid bacteria (LAB) in ensilages is still limited. Paenibacillus strains are important microbes in sustainable agriculture. Here, P. panacisoli SDMCC050309 was isolated from ensiled corn stover and used as an example to investigate the effects on LAB. This strain produced at least 7 xylanases, and two of them were purified and characterized. Temperature and pH optima were determined to be 55 °C and 8.0 for Xyn10 and 40 °C and 7.0 for Xyn11, respectively. They could degraded larch wood xylan and alkali-pretreated corn stover into xylooligosaccharides (XOS). Using the produced XOS to culture Lactobacillus brevis SDMCC050297 and L. parafarraginis SDMCC050300, both of them grew well with high level of acetic acid production. The same phenomenon was observed when co-culturing those two Lactobacillus strains with P. panacisoli SDMCC050309. Therefore, P. panacisoli enhances growth of LAB by producing XOS in corn stover ensilages.