SCR catalyst modification is a common method, but the choice of modified elements often depends on experience. Therefore, the F, N, Cu, La and Ce doped V2O5/TiO2 catalysts are proposed to be discussed at the molecular level. The bond length, charge, total energy and density of states of F, N, Cu, La and Ce doped V2O5/TiO2 were calculated based on density functional theory (DFT). The results show that F, N, Cu, La and Ce doping form a stable structure by partially substituting Ti into the crystal structure of TiO2. The total energy is lower and the band gap is smaller than before, which is beneficial to improve the catalytic activity of the catalyst. The effect of Ce doping is more favorable for the catalytic reaction, which is obviously better than other elements. © 2020, Science Press. All right reserved.