The photo decomposition of formaldehyde (HCHO) in an air stream in a bamboo charcoal loaded Ce-doped TiO2 coated photo-reactor was systematically investigated and demonstrated to be effective at relatively short retention times. The TiO2 loading and the photo-reactor’s structure’s influences on the efficiency of photochemical catalysis degradation of formaldehyde was reviewed. The TiO2 / bamboo charcoal adsorption of formaldehyde, as well as the influences of a certain amount of formaldehyde after adsorption on its photochemical catalysis effect were discussed. The sol-gel preparation method was used to prepare TiO2. Compare a series of experiment data, we get: after supported by TiO2, the surface of bamboo Charcoal still has strong catalysis degradation ability. After adsorbing formaldehyde, the photochemical catalysis degradation efficiency of formaldehyde of the catalyst at steady state is generally the same with pure catalyst. When the thickness of the catalyst layer of the multi-ladder-type structure photo-reactor is 2mm, the interval is 20mm, the best absorption efficiency of formaldehyde of TiO2 / bamboo charcoal is reached. TiO2 without doped Ce has no degradation of formaldehyde after 2 hours, but the degradation rate of formaldehyde of the Ce-doped TiO2 still is 15% 2 hours later, and the formaldehyde decontamination of the equipment reached 94%.