Advanced oxidation processes with O3/UV are applied to treat the acrylic fiber wastewater which is biorefractory and has high microbial toxicity. Effects of reacting time, pH value and feed concentration of contamination on the treatment efficiency are systematically investigated. The results show that, with remarkable synergistic effect, the treatment of acrylic fiber wastewater with combination of O3/UV is more efficient than the simple fold of ozone and UV treatment. The B/C of the wastewater increased from 0.08 to 0.3 after treatment, which improved the biodegradability of fiber wastewater and benefits the followed-up biotreatment. The optimum treatment efficiency was achieved after 30 minutes when pH reaches 6. The COD value decreased from 1 120 mg/L to 850 mg/L, with the removd rate of 25%, and the B/C ratio of wastewater is increased to 0.34.