The utility model provides a cyclone separator with a damping device. The damping device is arranged in a core tube on the top of the cyclone separator. The damping device is provided with a section of circular-tube-shaped blade root coaxial with the core tube. A plurality of blades are arranged along the circumference of the blade root. A blade is a continuous smooth curved surface. An inner directrix of the blade on the spreading face of the outer wall of the circular-tube-shaped blade root is composed of a straight line section on the upper portion of the inner directrix and a smooth curve on the lower portion of the inner directrix. The straight line section is parallel with the axis of the circular-tube-shaped blade root. The integral of the circular-tube-shaped blade root and the blade constitutes the damping device. The cyclone separator with the damping device can convert a part of rotation movement of currents in the core tube into straight line movement, can convert rotation kinetic energy of a part of the currents into static pressure energy, can effectively reduce overall pressure drop of the cyclone separator, and therefore achieve the functions of drag reduction and efficiency increase. The damping device is low in cost and simple in structure, and has no moving components. The cyclone separator with the damping device can stably work for a long time under complicated working conditions.