The heterocyclic amine 2-amino-1-methyl-6-phenyl-imidazolium [4, 5-B] pyridine (PhIP), commonly found in roasted meat products, is considered a potential carcinogen. This study is to explore the underlying mechanisms involved in the adsorption of PhIP by lactic acid bacteria 37X-15 and its peptidoglycan. The scanning electron microscope results suggested that the strain's adsorption on PhIP occurs on the cell wall, primarily composed of peptidoglycan. The fourier-transformed infrared spectroscopy results indicated that PhIP adsorption by both lactic acid bacteria 37X-15 and its peptidoglycan primarily involved OH and NH binding groups. Different adsorption conditions affected the adsorption rate of PhIP by peptidoglycan. The optimal values for each adsorption condition were 2 h, 37 °C, and pH 6 when the maximum adsorption rate reached. This study provides a new direction for the application of lactic acid bacteria and its peptidoglycan in food safety.