Three different metal ions doped TiO2 photocatalysts, which were prepared by the sol-gel method, were immobilized to porous nickel mesh by coating. The photocatalytic degradation activity of the supported photocatalyst on formaldehyde and volatile organic compounds (VOCs) was investigated. The results show that the nanometer TiO2 has an anatase structure. The photocatalytic degradation rate of formaldehyde and VOCs of 1.5% La3+ doped TiO2 coated on porous nickel mesh at 90 min are: 94% and 87%, higher than undoped TiO2: 83% and 72%, Fe3+ doped TiO2: 62% and 62%, Ag+ doped TiO2: 86% [Chinese character: see text] 81%. The orders of photocatalytic degradation rate on formaldehyde and VOCs with different content of La3+ doped TiO2 are as follows: 1.5% > 1% > 2% > undoped, 1.5% is the optimum La3+ doped content. Decreasing circular wind speed and using 254 nm or 365 nm ultraviolet wavelength will not influence the photocatalytic degradation rate of formaldehyde and VOCs.