The utility model provides a device for cleaning a blackboard movably. The device comprises a water tank, a water hose, a push rod, a pull rod, a lifting rod and cleaning cloth, wherein the water tank is connected with one end of the water hose; the other end of the water hose is connected with the cleaning cloth; the bottom of the lifting rod is connected with the cleaning cloth; the top of the lifting rod is connected with the water tank; the lifting rod has a telescopic structure; the upper part of the pull rod is connected with the lifting rod; a pulley is arranged on a contact surface between the lower part of the water tank and the top of the blackboard; the upper part of the push rod is connected with the side face of the water tank; a sealing cover is arranged at one end, which is connected with the cleaning cloth, of the water hose. The device for cleaning the blackboard movably provided by the utility model has the advantages of simple structure, convenience in installation, easiness and convenience in operation, low cost, realization of easy and complete cleaning of the blackboard and worth of popularization and application.