The invention relates to a coal chemical wastewater treatment system. The system sequentially comprises the following devices in treatment processes: an oil-water separation air floatation treatment device, an extraction device, a bioreactor, a nano micro-gas ozone treatment device, a reverse osmosis device and a follow-up treatment device. The coal chemical wastewater treatment system provided by the invention can realize purification treatment of coal chemical wastewater, and while various products are obtained, the treated wastewater can be used for industrial application. The coal chemical wastewater treatment system has good economic values and good market prospects; the cost for treating each ton of the coal chemical wastewater by using the coal chemical wastewater treatment system provided by the invention is about 30 Yuan RMB; however, the value of the products including petroleum type, benzene type and phenol type substances and the like in the products obtained after wastewater treatment is 60 Yuan RMB, and the value of the treated pure water which is recyclable is 10 Yuan RMB.