The invention relates to a counter-rotating axial flow pump driven by a single motor. The counter-rotating axial flow pump comprises a working motor and a transmission main shaft. The transmission main shaft is sequentially provided with a flow guiding cap, a front impeller, a rear impeller and a fixed guide vane in the direction from a pump inlet to a pump outlet. The front impeller is mounted ona front impeller hub. The transmission main shaft drives the front impeller to rotate in the direction the same as the rotation direction of the transmission main shaft through the front impeller hub. The rear impeller is mounted on a rear impeller hub. The fixed guide vane is mounted on a fixed guide vane hub. The interior of the flow guiding cap, the interior of the front impeller hub, the interior of the rear impeller hub and the interior of the fixed guide vane hub form a closed cavity. The cavity is internally provided with a bevel gear set transmission device. The transmission main shaft drives the rear impeller to rotate in the direction opposite to the rotation direction of the front impeller through the bevel gear set transmission device. The counter-rotating axial flow pump is compact in structure; the clearance formed between the front impeller and the rear impeller is small; the axial dimension is large; the flow is large; the lift is high; and the wide application prospect is achieved.