The invention discloses a methylsulphonic acid system bismuth sulfide concentrate normal pressure oxygen enrichment leaching method. The method comprises the following steps that 1, material pretreatment is carried out, wherein bismuth sulfide concentrate is added into a vertical mill, the vertical mill is used for carrying out fine grinding on the bismuth sulfide concentrate, then the treated bismuth sulfide concentrate is dried, and the bismuth sulfide concentrate for standby application is obtained; 2, solution preparation is carried out, wherein elementary substance iron powder is added into a methylsulphonic acid solution, the solution is stirred, the elementary substance iron powder and the methylsulphonic acid solution react fully, and the methylsulphonic acid leaching agent containing iron is prepared. According to the method, the wet extraction technology is adopted for replacing the traditional pyrogenic process technology, bismuth is leached out at normal pressure in a methylsulphonic acid system, the bismuth leaching out rate is high, sulfur exists in slag in the form of elemental sulfur, generation of low-concentration sulfur dioxide is avoided from the source, meanwhile, the leaching out condition is mild, the energy consumption is low, production operation is benefitted, and the method is simple in technological process and convenient to use and popularize.