Ventilation compensation structure after elevator is additionally installed in existing house

The ventilation compensation structure comprises an elevator car body, the front end of the elevator car body is movably connected with an elevator protection opening and closing door, and a ventilation mechanism is positioned at the upper end of the elevator car body. According to the ventilation compensation structure after the elevator is additionally installed on the existing house, the ventilation mechanism can conveniently conduct ventilation compensation on the interior of the elevator car body, after the control motor is started, the suction fan connected with the connecting rotating rod is driven to rotate, air in an inner cavity of the elevator car body is sucked out and conveyed out, and ventilation compensation is conducted on the interior of the elevator car body. A negative pressure environment is formed in the elevator car body, when air is exhausted, new air is sucked in from the purifying and filtering dustproof net and the purifying and filtering pipe, the air is filtered through the activat