With the continuous improvement of environmental protection requirements, the discharge of secondary fiber industry including waste water, gas and sludge were controlled more strictly. The toxicity studies on coated white board effluents of secondary fiber were carried out by using optimized photo bacteria method. The results showed that the value of EC50 for acute toxicity in coated white board effluents, which were produced from liners effluents and integrated effluents, were 85.50% and 89.77% respectively, reached the level of Moderately Toxic, by contraries from barrier coating effluents, was 157.57%, belong to Non-Toxic Class. Therefore, it should be pay more attention to the toxicity and toxicity emission load of coated white board effluents. Additionally, it can be seen from the analysis of organic compositions that key toxicant produced by liners effluents was diethyl phthalate. And there were no key toxicants of barrier coating effluents.