Dust filtering ventilator

The utility model relates to the technical field of ventilating fans, in particular to a dust filtering ventilating fan which comprises a first shell, a limiting device is arranged at the top of the first shell and comprises a second track plate, the bottom of the second track plate is fixedly connected with the top of the first shell, and the top of the second track plate is fixedly connected with a first track plate. A rail is formed between the first rail plate and the top of the first shell, a baffle is fixedly connected to the inner wall of the second rail plate, telescopic damping rods are fixedly connected to the two sides of the baffle, first springs are arranged on the outer surfaces of the telescopic damping rods, and one ends of the telescopic damping rods are fixedly connected with a moving plate. Second shifting blocks are fixedly connected to the tops of the two moving plates, the second shifting blocks can be shifted, the moving plates are driven to move, the first springs are compressed, then