The invention relates to an oil-water separator of a circulating fluidized bed, which comprises a lifting pipe, wherein a liquid inlet is arranged at the bottom of the lifting pipe, the liquid inlet is communicated with a liquid storage tank, a liquid inlet distribution plate is arranged above the liquid inlet, a plurality of oil absorption particles are stacked on the liquid inlet distribution plate, and a material inlet and outlet and a material return port are positioned on side wall of the lifting pipe, the material inlet and outlet and the material return port are all positioned above theliquid inlet distribution plate; a descending pipe, wherein the top of the descending pipe is provided with a liquid-solid cyclone separator, the liquid-solid cyclone separator is communicated with the upper part of the lifting pipe through a connecting pipe, and an overflow port at the top of the liquid-solid cyclone separator forms a first liquid outlet; a material return pipe, wherein one endof the material return pipe is communicated with the bottom of the descending pipe, the other end of the material return pipe is communicated with the material return port, and the material return pipe is provided with a second liquid outlet. According to the invention, the secondary separation of two phases of oil and water can be achieved through the adsorption action of oil absorption particlesand the centrifugation action of the liquid-solid cyclone separator, and the oil-water separation efficiency is improved.