Abstract: The influence of HPAM, pyrrolin and pyrrolin/HPAM system on the stability of crude oil emulsion was studied through dehydration and interfacial properties experiment in this paper. The result indicated that when different oil-displacing agents with concentration of 100 mg/L were added in emulsion, the dehydration rate decreased by 15% and the SV value increased, the stability of crude oil emulsion was strengthened by all oil displacing agents. The conductivity and Zeta potential value of the water phase increased with demulsification, the median size of oil droplets decreased, then the coalescence of oil droplets was difficult. The stability mechanism of different oil-displacing agents was different: HPAM had no obvious influence on interfacial tension but made the emulsion stable by increasing its viscosity; however, pyrrolin greatly reduced the interfacial tension and had no influence on viscosity. The synergistic effects of the two oil-displacing agents made the emulsion more stable.