In order to improve the stability of crude oil emulsion，the dispersion stabilities of hydrophilic and hydrophobic alumina nanoparticles in anionic surfactant sodium dodecyl benzene sulfonate （SDBS），cationic surfactant cetyltrimethyl ammonium bromide（CTAB）and nonionic surfactant alkylphenol ployoxethylene ether（OP-10）were studied. O/W emulsion was prepared by alumina nanofluids，liquid paraffin and OP-10. The effects of hydrophilic and hydrophobic nanoparticles and OP-10 on emulsion stability were investigated. The results showed that the surfactant type and concentration had great influence on the dispersion of alumina nanoparticles，and the dispersibility of OP-10 was better. The stability of O/W emulsion was closely related to nanoparticle and surfactant. On a certain concentration，with increaseing concentration of nanoparticle and surfactant，the interfacial tension between oil and water decreased as well as the stability of emulsion enhanced. High concentration of nanoparticle and surfactant could increase the interfacial tension and water separation rate and decrease the stability. The emulsion composed of 0.3% OP-10 and 0.2% hydrophobic alumina nanoparticle had good stability. Compared with hydrophilic alumina nanofluids，hydrophobic alumina nanofluids exhibited higher dispersion stability and stronger ability to stabilize O/W emulsion.