The adsorption characteristics of arsenic and selenium by CaO, CaCO3, MgO and Fe2O3 at different temperatures and the influence of steam are investigated using simulated flue gas by a vertical furnace. Experiments show that the adsorption capacity of CaCO3 for arsenic and selenium reached the maximum at 900 °C. Steam addition exerts a notable inhibitory impact on the adsorptive efficacy of CaO, MgO, and Fe2O3. Low-concentration steam has a certain improvement on adsorption of arsenic by CaCO3, while excessive steam will have an inhibitory effect. Based on CaCO3, the adsorption effect of composite minerals is investigated. When the mass ratio of CaCO3 and Fe2O3 is 3:1, the best adsorption is achieved, attributing to the generated Ca2Fe2O5 at high temperature. It is verified in the drop tube furnace. The relative enrichment factor of As and Se are 88.24 % and 75.11 %, respectively, which achieved efficient removal.