The intestinal microbial metabolism of procyanidin B1 was explored by using porcine caecal microorganisms through static culture in vitro. Under anaerobic operating conditions， firstly， we obtained the intestinal microorganisms from the cecal lumen of freshly slaughtered pigs， which required for the incubation model， then incubated the procyanidin B1 in prepared the culture medium， and collected the incubation solution at 0， 2， 4， 6， 10， 18 h， Use UHPLC-TOF-MS/MS to detect metabolites at different time points， and use non-targeted metabolomics analysis methods to determine differential metabolites in the metabolic process of procyanidin B1， and analyze metabolic pathway of procyanidin B1. Results showed: 21 kinds of metabolites were screened and identified. The metabolism of procyanidin B1 by the intestinal flora was fairly rapid， and it was exhausted at 6 h； the metabolites catechins and 5-(3'，4'-dihydroxyphenyl)-γ-valerolactone was produced in large quantities between 2-4 h； Phenylpropionic acid and benzoic acid were the main metabolites， which reach a peak at 6 h and continued producing between 4-18 h. Analyze the metabolic pathways of procyanidin B1 based on the results above. We believed that procyanidin B1 can be metabolized through three pathways， namely: the flavan bond breaks， the lower structure forms catechins， and the catechins further open the C ring to form catechins. C-ring-opening product； the lower structural unit of procyanidin B1 undergoes cleavage of the A ring to form phenyl-γ-valerolactone； the cleavage of the upper structural unit of procyanidin B1 directly forms phenolic acids.