The invention discloses a method for separating and recycling sulfur, iron and selenium from selenic acid mud, which comprises the following steps: firstly, adding elemental sulfur soaked in kerosene into selenic acid mud, filtering and separating hot kerosine containing the elemental sulfur and desulfurization slag containing selenium and iron; separating the elemental sulfur out after cooling the hot kerosene; secondly, adding the desulfurization slag containing selenium and iron to a mixture solution of sulfuric acid and sodium chlorate, filtering and separating oxidized leaching solution and residual slag containing iron, adding sodium sulfite and thiourea into the oxidized leaching solution sequentially, and finally obtaining coarse selenium and a solution after selenium sunk throughreduction. The total recovery rate of sulfur is 97- 98%, the grade of selenium reaches 92-93%, and the total recovery rate of selenium is 94-95%. The invention has the advantages of convenient operation, simple equipment and high value in application.