The invention discloses a method for refining and enriching element gold by utilizing selenium ether, and relates to the technical field of refining and enrichment of precious metal elements. According to the method, an isocyanate, a selenium-containing small molecule compound, a cross-linking agent and a tin-containing catalyst are utilized to prepare a selenium-containing porous material, or a selenium-containing polymer is prepared by using the isocyanate, the selenium-containing small molecule compound and the tin-containing catalyst; the selenium-containing porous material or the selenium-containing polymer is immersed in an aqueous solution containing free-state element gold to stand until the element gold is completely precipitated; and the selenium-containing porous material or theselenium-containing high molecule on the surface of the precipitated element gold is removed, and a refined and enriched gold elementary substance is obtained. According to the method, based on the interaction between the reducing property and coordination of the element selenium, the selenium-containing porous material is prepared by adopting different material synthesis methods while the molecular structure of the selenium-containing small molecule compound is adjusted. A prepared material can realize environment-friendly, efficient, and high-selectivity reduction and enrichment on free element gold in multi-metal ion component electronic waste water.