The degradation of formaldehyde via TiO2 photocatalysis coupled with dielectric barrier discharge was investigated, which aimed to reveal the effects of discharge voltage, catalyst support, calcination temperature and transition metal ion-doping on the degradation efficiency of formaldehyde. The results indicated that (1) TiO2/γ-Al2O3 photocatalyst improved the degradation efficiency of formaldehyde and the products selectivity significantly; (2) the degradation rate increased with increasing discharge voltage or decreasing calcination temperature; when the discharge voltage was 20.7kV and the calcination temperature was 400℃, respectively, the degradation rate reached 83.8%; (3) plasma-driven anatase TiO2 system showed the best degradation efficiency compared to the plasma-driven rutile TiO2 system and the plasma-driven mixed crystal system; (4) after Mn ion-doping, the degradation rate increased 45.7% compared to the system with plasma alone, while the ratio of CO/CO2 and O3 concentration decreased about 42.5% and 39.4%.