Objective: The effects of Moringa oleifera leaf extract on the growth of Lactobacillus were systematically evaluated， and the characteristics of its growth-promoting effect were explored. Methods: The effect of M. oleifera leaves extract on the growth of Lactobacillus was evaluated by in vitro pure culture method， and the combination of M. oleifera leaves extract and Lactobacillus with promoting effect was screened； the main components of the ethanol-soluble part of M. oleifera leaves aqueous extract (MAES) were detected by plant MRM broad targeting metabonomics technology， and its growth-promoting characteristics were evaluated from the aspects of biofilm characteristics， extracellular protein， total sugar and reducing sugar content， freezing and salt tolerance. Results: The aqueous extract of M. oleifera leaves (MAE) and MAES showed low promotion or inhibition on the growth of Lactobacillus， MAES could stimulate the growth of Lacticaseibacillus casei (LCA) at low concentrations (0.08%) and the promotion rate was 16.63%. MAES was rich in flavonoids， amino acids and nucleotides， which could promote the formation of LCA biofilm and increase the adhesion， surface hydrophobicity and acid-base charge of the biofilm； at the same time， the secretion of extracellular protein was promoted， and the contents of reducing sugar and total sugar were increased (P < 0.01)； the antifreeze ability of LCA and the activity of β-galactosidase were also improved significantly (P < 0.01). In addition， MAES improved the NaCl tolerance of LCA. Conclusion: MEA had both low promoting effect and inhibiting effect on the growth of Lactobacillus. MAES could promote the growth of LCA by promoting the formation and adhesion of biofilm， increasing the content of extracellular protein， total sugar and reducing sugar， and enhancing the tolerance.