In this paper, we have studied the photocatalytic activity of TiO2 which was modified by ferric stearate; ferrocene and nickel N,N-dibuty dithiocarbamate (NiDBC) , respectively. Innovatively, methylene blue (MB) was used as model pollutant. Under visible light irradiation, this paper studied the effect of the photocatalytic degradation of MB. The result shows that when the mass ratio is 5:1, the catalytic effect is C>B>A. When mass ratio is 1:1, the catalytic effect is B>C>A. Another result shows that with the increase of the amount TiO2, catalytic effect of TiO2 modified by ferric stearate significantly increases, otherwise, TiO2 modified by ferrocene and NiDBC were different.