A large amount of emulsion is easily formed in the process of crude oil production due to the active components， including asphaltene，resin，petroleum acid and wax. Based on the composition and existing state of active components in crude oil，the influence mechanism of each active component on the stability of emulsion was described. The interaction between active components and asphaltene with their influence on emulsion stability was summarized. Among the active components of crude oil， asphaltene was the main component of interfacial film，and suitable resin with asphaltene could strengthen the emulsifying effect. The effects between carboxylic organic acids with different relative molecular mass and asphaltene were various，and the wax could enhance the strength of interfacial film when they crystallized or interacted with asphaltene. Meanwhile，current problems and future development directions were prospected.