Aimed at the spontaneous oil-in-water emulsified phenomenon in low acid high phenol crude oil，the components of the crude oil separated by column chromatography method were analyzed and characterized quantitatively by Fourier transform infrared spectroscopy and Orbitrap mass spectrometry. Then according to the molecular characterization of crude oil，interfacial activity between crude oil components and heavy alkyl benzene sulfonate，NaCl and NaHCO₃ solution was determined and discussed， respectively. Results showed that the relative content of phenols was higher and chain fatty acids in resins were important components in low acid high phenolic crude oil. The oil-solution interfacial tension increased significantly after the removal of petroleum acids. Phenols which had larger relative content than acids in crude oil could promote emulsification. For alkaline solution，phenols，naphthenic acids and chain fatty acids could reduce interfacial tension. However，the interfacial activity between phenols and other solution was lower. Only chain fatty acids could reduce interfacial tension.