The invention discloses a process for treating 
tar product 
wastewater, which can improve the ratio of BOD / COD of the 
wastewater, reduce the concentration of 
ammonia thereof and the concentration of volatile 
phenol, and further lead the 
wastewater to be recycled or discharged without 
pollution. The process for treating the 
tar product wastewater is characterized in that: a. the wastewater which is generated by cleaning is conducted into a primary 
settling tank to be settled so as to remove the settled impurities; b. the wastewater is conducted into a wastewater circulating 
pool so as to remove big granular matters, partial suspended matters and partial oil, and reduce the content of COD; c. the wastewater is conducted into a coagulating air floating 
machine so as to remove the oil, 
slag, 
ammonia and 
nitrogen; d. the wastewater is conducted into an intermediate 
settling tank to settle the impurities of the coagulating air floating tank and simultaneously regulate the 
water quality; e. the wastewater is conducted into a hydrolytic acidification tank and the function of an anaerobe is utilized so as to degrade the 
refractory organic matters with big particles and molecules into biodegradable organic matters with small molecules; f. the wastewater is conducted into a contact oxidation tank, and under the contact oxidation action of 
aerobic bacteria, through 
aeration, the organic matters in the wastewater are absorbed and degraded by the 
aerobic bacteria; and g. the wastewater is recycled or discharged after reaching the standards after being settled by the inclined 
settling tank and treated by the post-treatment process.