Abstract: The service life of catalyst is an important factor to decide the stability of the processing efficiency in the active carbon fiber (ACF) loaded titanium dioxide photocatalytic oxidation of organic waste. The methods such as ultraviolet ray with steam and the ultraviolet ray with ozone were studied for observing the condition of ACF and catalyst in the process. The catalyst life was determined according to the deactivation rate while the test was finished when the efficiency was stable. On the basis of tentative data，an effective method enhancing resistance to deactivation of titanium dioxide was presented.