To investigate the different effects of different ionic emulsifiers on the stability of emulsified asphalt， based on molecular dynamics simulation， the double-layer model structure of “asphalt-emulsifier-water-emulsifier-asphalt” was constructed by using Materials Studio software， and emulsified asphalt systems containing different ionic emulsifier molecules were simulated to compare the effect of anionic （SDS）/cationic （CTAC） emulsifiers on the stability of emulsified asphalt. The changes in the relative concentration distribution， interfacial film thickness， interfacial formation energy， and electrostatic potential （ESP） of the asphalt emulsions were compared with the addition of different emulsifier molecules in order to analyze the stability of the emulsified asphalt. The results show that the SDS emulsifier increases the thickness of the interfacial layer between asphalt and water， reduces the interfacial tension between the two phases， and improves the stability of the emulsified asphalt， compared with the CTAC emulsifier. From the perspective of electrostatic potential analysis， compared with CTAC emulsifier， SDS emulsifier molecule has a larger maximum electrostatic potential of the alkane chain， and it is more likely to bond with atoms with negative electrostatic potential. Therefore， the overall stability of emulsified asphalt with an SDS emulsifier is better than that of emulsified asphalt with a CTAC emulsifier.