The wastewater from the coke plant is of poor biodegradability with high concentrations of ammonia and organic pollutants. The engineering application research of enhanced microbiological treatment for coking wastewater was carried out in a coking plant located in Heilongjiang province. The daily capacity of the project is 1600 cubic meters. The system including bioreactors was started up successfully in winter. The CODCr and ammonia nitrogen contents of influent were 2500mg/l and 260mg/l respectively and the effluent met the requirements of first grade standard in "Integrated Wastewater Discharge Standard" (GB 8978-1996). Compared with traditional full nitrification denitrification process, the project has such feathers as lower energy consumption, smaller area occupation, less alkali adding, lower excessive microorganisms production, lower construction and operation costs and higher processing efficiency.