The invention discloses a process for recycling lead zinc, silver and iron from tailings after carrying out sulphur flotation on zinc oxygen pressure leaching slag and belongs to the field of non-ferrous metal smelting and recycling. The process disclosed by the invention mainly comprises the following steps of: metallization roasting, magnetic separation, electrolysis and the like; lead zinc is recycled in a smoke dust form during metallization roasting; iron is recycled in a form of electrolytic iron powder; and silver is recycled as a silver smelting raw material. Compared with the prior art, the recycling indexes of the process disclosed by the invention have the advantages that the recovery rates of lead zinc, silver and iron are obviously improved, the recovery rates of lead zinc and silver are higher than 90wt%, and the recover rate of iron is 89-93wt%; besides, the electrolytic iron powder produced through magnetic separation-electrolysis can be used for obviously improving the value of the iron in the tailings after sulphur flotation is carried out on the oxygen pressure leaching slag; and the process disclosed by the invention has obvious effect, separate recycling of Fe with Pb+Zn and Ag is realized, stockpiling of quantity of oxygen pressure leaching slag is reduced to the utmost extent, and an effective production method is provided for comprehensive recycling of zinc leaching slag and even other non-ferrous metal smelting slags.