The utility model discloses a coking waste water processing device, comprising an oxygen-poor reactor, a first section of aerobic reactor, a second section of aerobic reactor, two settling tanks, a coagulation reaction drug dissolving device, a coagulation reactor and a coagulation settling tank which are connected in series, wherein the output end of the second section of aerobic reaction is connected with the input end of the oxygen-poor reactor through a mixing fluid reflow pipe and a pump, and the output ends of the two settling tanks are connected with the input end of the oxygen-poor reactor through a mud reflow pipe and the pump. The device is suitable for disposing waste water by a biochemical method. The yielding water CODCr is lower than 100mg/l, and the ammonian is lower than 5mg/l. The operating fee by adopting the device to dispose the waste water is low. The experiment shows the fee is only 3.2 RMB per ton. The operation is stable, the water yielding effect is good, the maintenance is simple and convenient and the popularization and the application are convenient.