The triethylamine and epoxy chloropropane are taken as materials to synthesize the intermedium of glycidyl and triethyl ammonium chloride asphalt emulsifier by reaction,which is then quatemized by means of octadecylamine to obtain the quaternary ammonium salt type cationic asphalt emulsifier.The test shows that the pH value of emulsifier solution has the maximal influence on emulsifying effect.