It was studied that the organic pollutant in the industrial wastewater was degraded with the photocatalyst of conted nanometer sized titanium dioxide by the method of orthogonal test from the angle of photocatalytic chemistry in this paper. The factors concerned to influence the rate of degrading the organic pollutant in the industrial wastewater were discussed and the optimum conditions to degrade organic polutant were determined. It was thought that the mass percentage of nanometer sized titanium dioxide in the photocatalyst was main factor to influence the rate according to the experiment.