The present invention discloses a method for preparing a novel biological fluidized bed carrier by using waste coke powder and treating waste water. According to the method, active sludge is inoculated in a biological fluidized bed main body, a biological fluidized bed carrier is poured, membrane forming culture is performed, waste water enters a reflux groove through a water pump, concurrently partial effluent of the reflux groove refluxes to the reflux groove, an influent pump is adopted to pump the waste water in the reflux groove into the biological fluidized bed, and water quality of effluent on an upper effluent port of a precipitation tank is monitored, wherein standard discharge is performed if a concentration of effluent COD is less than 100 mg/L and an ammonia nitrogen concentration is less than 10 mg/L, if the standard is not met, the effluent enters the reflux groove through a three-way valve to be continuously treated. According to the carrier, a good turbulent flow effect is provided in the fluidized bed, efficiency is high, a sufficient specific surface area can be provided, membrane forming is easily achieved, no toxic and harm effect is generated, and the carrier is easily fluidized in water and does not easily run off. In addition, the carrier adopts waste coke powder as the raw material, such that material taking is easy, the material source is wide, price is low, and the waste coke powder is subjected to resource utilization so as to change waste into valuables.