Abstract: The modified process of activated carbon felt,which is coated with nano-TiO2by sol-gel technique,and the experimental method of removing formaldehyde using the felt are studied.The influences of factors,such as dip-coating times,thermal treatment temperature,dip-coating time and heating rate etc.,on removing effect of formaldehyde are evaluated using orthogonal experimental method.The results show that dip-coating times is the biggest influence factor,followed by thermal treatment temperature.However,dip-coating time and the heating rate have little influence.The best removing result is obtained on following conditions : dip-coating times twice,thermal treatment temperature within 400-450℃,dip-coating time 10 min and the heating rate 3℃/min,the adsorption-conversion amount is 96.33μg/g.