The invention discloses a blackboard eraser preventing chalk dust from flying. The blackboard eraser comprises a box. An inner cavity is arranged in the box. A battery, an electrostatic generator and rotating shafts are arranged in the inner cavity. A supporting rod is arranged between the rotating shafts. The rotating shafts and the supporting rod are sleeved with a piece of wiping cloth in a connected manner. The outer side portion, facing the box, of the supporting rod is fixedly connected with an elastic gasket. The elastic gasket is located between the supporting rod and the wiping cloth. The electrostatic generator is electrically connected with the supporting rod. The battery is electrically connected with the electrostatic generator and the rotating shafts. The wiping cloth is made from a conductive material. The blackboard eraser preventing the chalk dust from flying is made by the adoption of the physical character that an electrified body attracts tiny objects and is suitable for various blackboard erasers, beneficial for popularization, simple in structure, convenient to use, environmentally friendly and high in efficiency.