Based on the increasingly serious formaldehyde pollution,the effective degradation of formaldehyde has become a practical problem urgently to be solved. Activated carbon prepared from biomass materials,coal with different metamorphic degrees and petroleum coke has the advantages of large specific surface area,high adsorption efficiency,which has significant advantages in adsorption and separation of formaldehyde pollutants.The activated carbon adsorption mechanism and modification,TiO2 photocatalytic reaction principle,ways to improve the photocatalytic activity,TiO2 load were reviewed,and the adsorption and degradation properties of formaldehyde on activated carbon and TiO2/AC were analyzed and compared,and the future research direction of activated carbon modification and TiO2/AC adsorption-photocatalysis was also prospected. Activated carbon is mainly physical adsorption,which will desorb under certain pressure and temperature conditions,resulting in secondary pollution. The pore size distribution and surface acid functional group content of activated carbon can be changed by acidification modification,and the physical adsorption can be changed into physical-chemical combined adsorption,which can effectively improve the adsorption of formaldehyde molecules on the surface of activated carbon. In addition to adsorption by activated carbon,TiO2 is non-toxic,harmless,safe and green,with high photocatalytic efficiency,and is generally recognized as an-ideal-material for photocatalytic degradation of pollutants such as formaldehyde. According to the photocatalytic principle of TiO2,pollutants such as formaldehyde can be catalyzed into CO2,H2O or other inorganic small molecules through two active species with strong oxidation capacity —OH and —O-2. However,the large-scale industrial application will be limited due to the problems of low quantum efficiency,narrow absorption range of visible light and low reusability of TiO2. After metal ions are doped into TiO2,a shallow trapping potential well of electrons and holes is formed. After nonmetallic anions replace the oxygen position of TiO2,the degree of structural distortion is changed,which reduces the electron-hole pair recombination to a certain extent. Semiconductor with different band gap width can be combined to form a heterojunction by compound sensitization,which can broaden the spectral response range of the compound catalyst. TiO2/AC adsorption and catalytic co-material prepared by supporting TiO2 on activated carbon is conducive to solving the problem difficult recycling of catalyst. The absorption and concentration by activated carbon provides a good reaction environment for photocatalysis and improves the degradation rate. Activated carbon with specific adsorption ability can be developed by controlling activation and carbonization process. With the in-depth study of TiO2 mechanism,TiO2/AC materials with high removal efficiency,large adsorption capacity,low energy consumption and selectivity are prepared to improve the preparation level of adsorption catalytic co-materials,which is conducive to the realization of the technical goal of efficient and clean degradation of formaldehyde.