This study aimed to evaluate the effects of wilting and exogenous lactic acid bacteria treatments on the chemical composition, fermentation quality, and microbial community composition of Plantago lanceolata silage (PS). This experiment was carried out in the Guizhou Extension Station of Grassland Technology (25°38′48″ N, 106°13′6″ E). The PS samples were divided into four treatment groups, namely control PS (C-PS), wilting-treated PS (W-PS), Lactobacillus brucei-treated PS (LB-PS), and wilting + L. brucei-treated PS (WLB-PS) groups, and analyzed after 60 d of treatment. The W-PS and WLB-PS groups showed significantly lower ether extract, ash, and Neutral detergent fiber contents but significantly higher water-soluble carbohydrate content compared to the C-PS and LB-PS groups (p < 0.05). Additionally, the W-PS group had significantly lower propionic acid content but significantly higher butyric acid content compared to the other groups (p < 0.05). Meanwhile, the WLB-PS group had the highest lactic acid content, the lowest pH, and no butyric acid content (p < 0.05). Additionally, the WLB-PS group showed a high proliferation of beneficial bacterial species (Lactobacillus buchneri and Lactobacillus plantarum) and decreased proliferation of undesirable bacterial species (Clostridium lutlcellarli and Clostridium tyrobutyricum). In conclusion, the combination treatment with wilting and L. brucei increased beneficial microorganisms and inhibited undesirable microorganisms during ensiling, thereby improving the fermentation quality of PS. Therefore, the combination treatment with wilting and L. brucei may be an effective Plantago lanceolata silage modulation technique.