In view of the problems of poor safety，leakage and large reservoir pollution in the process of workover of sour gas fields containing H₂S，CO₂，SO₂ and other acid gases in Sichuan and Chongqing area，a liquid gel plug system suitable for high-acid gas wells was obtained by optimizing vegetable gum thickener，adjusting pH value，adding antacid inhibitor. The rheological properties of the system，as well as the pressure bearing capacity，temperature stability，hydrogen sulfide resistance，and gel breaking performance after gel formation were investigated，and the field application in high-acid gas wells was carried out. The gelling time of the system，composed of 3% thickener，3% thickening dispersant，7% cross-linking agent，5% conditioner，1% acid inhibitor and regulator，was adjustable from 28 min to 200 min. The viscosity after gelling was greater than 30 Pa·s，indicating that the strength of the system was high. The gel did not break after aging for 24 h at the temperature of 150 ℃，and the gel did not break when soaked in the acid gas layer water containing 300 mg/L H₂S or 100 mg/L CO₂ for 72 h. The pressure bearing capacity was the best when the pH value of the system was 8. When adding the blockage relieving fluid，the liquid gel plug could be broken within 1—6 hours at the temperature of 50—80 ℃，and the viscosity of the broken fluid was lower than 3 mPa·s. The liquid gel plug system had been successfully applied in wells with H₂S content of 80 mg/L，which provided the technical support and guarantee for the well repair in Sichuan and Chongqing acid gas field.