A series of Mn−V−W/TiO 2 (Mn−VWT) catalysts were synthesized by the impregnation method and calcinated at different temperatures (300−600 °C). To explore the effects of the reaction temperature, SO 2 , and H 2 O on the simultaneous removal performance of elemental mercury (Hg 0 ) and NO, Mn−VWT were investigated by a fixed-bed reaction system. Various techniques (scanning electron microscopy, Brunauer−Emmett−Teller, X-ray diffraction, H 2 -temperature-programmed reduction, NH 3 -temperature-programmed desorption, and X-ray photoelectron spectroscopy) were utilized to characterize the samples. The results showed that the catalytic activity of Mn−VWT first increased and then decreased with the increasing calcination temperature. The removal efficiency of Hg 0 and NO still had good performance even in low reaction temperature (200 °C), achieving 100 and 82%, respectively. Mn−VWT-400 had the best simultaneous removal performance because of the highest content of the Mn 4+ , V 4+ , and chemisorbed oxygen O α and the best reductive activity at low temperature. Furthermore, SO 2 irreversibly inhibited Hg 0 and NO removal ability due to the sulfate and sulfite generation on the surface of Mn−VWT-400. Especially, the inhibition effect was more serious if SO 2 and H 2 O coexisted because the rate of sulfate/sulfite was higher than that of the former. In addition, with the increase in reaction temperature, the effect of SO 2 and H 2 O on the removal of Hg 0 and NO over Mn−VWT was gradually reduced.