The invention provides thiobacillus acidophilus. The name of the strain is Thiobacillus ferrooxidans ST-A, the Thiobacillus ferrooxidans ST-A is preserved in the China Center for Type Culture Collection (located in Wuhan University) on May 24, 2015, and is assigned with the accession number of CCTCC NO:M2015333. When the strain is adopted for treating iron-containing acid mine wastewater, divalent iron ions are oxidized in an acceleration manner under low pH, and then trivalent iron ions are generated; under the suitable pH, the strain can catalyze the trivalent iron ions to form schwertmannite (Fe8O8(OH)6(SO4)) sediment, so that the iron resource is effectively recycled, meanwhile, the recycled iron-containing sediment does not contain other valuable metal (copper, zinc and the like), and thus an operable process is provided for the resource recycling of metal in the acid mine wastewater.