In order to obtain high temperature microemulsified acid and provide novel acids for deep acidization of oil and gas fields,a novel high temperature microemulsified hydrochloric acid system with cationic Gemini surfactant propylene-1,3-bis(octadecyl dimethyl ammonium chloride)(18-3-18)as main emulsifier,n-butanol and n-octanol as assistant emulsifier,diesel as oil phase and hydrocholoric acid as acid phase was prepared in this paper. The thermal stability,phase behavior,retarded reactivity and CaCl2 toleran...