The conventional acid fluid stimulation system has inferior high-temperature stability，fast acid rock reaction rate and problematic demulsification. To solve the mentioned problems，a high temperature resistant PGA retarded acid was prepared using polyglycolic acid fluid as the inner phase acid fluid and diesel oil as the outer phase，and adding appropriate surfactants and other additives. The properties of the system，including the stability，shear resistance，acid production capacity，dissolution，were evaluated. The results showed that the optimized PGA retarded acid could remain emulsified state for 76 h at the temperature of 90 ℃. The system could produce 7.91 mol/L H⁺ within 3 h at the temperature of 130 ℃，and more than 9 mol/L H⁺ at continuous reaction. The final apparent viscosity of the system under sheared for 120 min was 31.22 mPa?s and 28.4 mPa?s at the temperature of 130 ℃ and 150 ℃ ，respectively，which conformed to the requirements of the national standard. The static retarded rate of the system to the core was 2.7 times and 2.1 times higher than that of the same concentration of the mud acid and the multiple hydrogen acid system，respectively. In acid-rock reaction experiments，the system could reduce the acid reaction rate by one or two orders of magnitude compared with the multiple hydrogen acid and mud acid system. the static corrosion rate of the system to N80 steel slice was only 3.453 g/（m²?h），which was lower than the standard value. PDA retarded acid exhibited well slow-release performance and weak corrosion，moreover，the degradation products was harmless，which met the requirements of filed processes and had good prospects for sustainable development.