The invention discloses an elevator ventilation device. The elevator ventilation device comprises an elevator car, wherein a mounting box is arranged at the top end of the elevator car. First groovesare formed in the two sides of the top end of the mounting box, an electric telescopic rod is fixedly connected to the inner wall of the top end of the mounting box, the inner cavity of the mounting box is provided with a ventilation box, a third groove matched with the ventilation box is formed in the top end of the elevator car, a second groove is formed in the top end of the ventilation box, apartition plate is arranged in the center of the second groove in the front-back horizontal direction, the partition plate is connected with a power output end of the electric telescopic rod, sound insulation sleeves are movably connected to the inner wall of the periphery of the ventilation box, silencing columns are uniformly arranged in the inner cavity of the ventilation box, and first silencing pieces are uniformly arranged on the silencing columns. The elevator ventilation device and a ventilation method have the advantages that the ventilated air is fresh, the dust is easy to treat, andthe noise is low during ventilation.