A counter-rotating fan, comprising two impellers and a motor. The motor is used for driving the two impellers to rotate. The two impellers are axially spaced apart from each other, and are divided into a first-stage impeller and a second-stage impeller. When the counter-rotating fan operates, airflow is blown to the direction of the second-stage impeller by means of the first-stage impeller. At least one impeller has turns of blades arranged in the radial direction of the impeller. Blades of each turn are spaced apart from each other around a hub of the impeller, and a spacer ring is connected between two adjacent turns of blades. The counter-rotating fan is stable in rotation and good in cooling effect, it is not easy to deform, and the wind is strong in the center.