Abstract: Experimental study on jet bubbling wet flue gas desulfurization (FGD) by using steel slag as an absorbent was carried out, and mechanism of FGD reaction studied based upon components of steel slag emulsion variance after FGD reaction. Optimal experiment condition was concluded by considering concentration of steel slag emulsion and depth of jet pipe submerged. Experimental results showed that FGD efficiency could be reached over 70% when the concentration of steel slag emulsion was 25%, the depth of jet pipe submerged was 130 mm, and pH was 6.6-6.8. It was concluded that components of CaO, MgO, Fe₂O₃, Al₂O₃ contained in steel slag could be effective in FGD desulfurization, and content of f-CaO and MgO in steel slag emulsion decreased after the FGD reaction, thus avoid the problem of FGD by-product expansion in case of water caused by f-CaO and MgO. Comparative experiments were conducted by using steel slag emulsion and limestone powder as absorbents, and the results showed obvious agreement obtained by using steel slag emulsion and limestone as FGD reaction respectively, and therefore steel slag could be used as wet FGD absorber replacing limestone.