In recent years, with more and more geothermal well construction, acidizing and plug removal technology is gradually applied to geothermal well construction field, but conventional acidizing has limited effect on geothermal well stimulation, this paper is based on laboratory compatible corrosion test of cuttings and rock samples, corrosion test of N80 casing steel sheet, and study of anti-swelling, water washing resistance and iron ion stability in geothermal well Hancheng No. 1, the SM131 complex acid system suitable for this area was put forward. The successful application of SM131 complex acid system in geothermal well Hancheng No. 1 showed that this complex acid system was effective in acidizing and plugging removal of well No. 1, the production capacity increased by 2.28 times and the temperature increased by 1.3 ℃, thus greatly reducing the production cost.