Objective: Kallikrein (KLK) is an important part of kallikrein kinin system (KKS)， which plays an important role in lowering blood pressure. Previous studies on the influence of food ingredients on KLK are limited. Methods: Eighteen vegetables (carrot， garlic， purple cabbage， baby cabbage， spinach， celery， leek， broccoli， enoki mushroom， bitter gourd， cucumber， yam， ginger， tomato， pumpkin， green pepper， potato， and shiitake mushroom) were extracted by water， ethanol and pepsin enzymolysis respectively， and their effects on KLK activity were determined. Seven vegetables (spinach， pumpkin， ginger， garlic， tomato， bitter gourd， and potato) were selected for protein extraction， followed by pepsin hydrolysis and in vitro simulated gastrointestinal digestion. Spinach-derived peptide with the strongest KLK-enhancing activity were isolated and purified via dextran gel chromatography and preparative high-performance liquid chromatography(HPLC). The amino acid sequence of the peptide was identified using secondary mass spectrometry， and molecular docking was performed to analyze its interaction mechanism with KLK. Result: Among the 18 vegetables， seven exhibited peptides significantly promoted the activity of KLK， while seven ethanol extracts significantly inhibited it from 18 vegetables. The polypeptide of spinach treated with pepsin and trypsin significantly enhanced KLK activity， which was a decapeptide with the amino acid sequence of His-Asn-Ser-Pro-Gly-Tyr-Tyr-Asp-Gly-Arg. The polypeptide has two docking points with KLK. N-terminal promotes the stability of KLK， and C-terminal plays a major role in promoting the activity of KLK. Conclusion: Enzymatic hydrolysates of garlic， pumpkin and potato enhanced KLK activity， whereas their ethanol extracts inhibited it. The spinach-derived peptide HNSPGYYDGR significantly promoted KLK activity.