The invention provides a medical intelligent ventilator comprising an expiration loop and an inspiration loop, which are connected with a breathing mask; the inspiration loop comprises an intelligent air-oxygen mixer, a bacterium filter, an inspiration valve, an inspiration flow meter, a pressure sensor A, a humidifying device and a heater, which are connected successively, the pressure sensor A being installed at the tail end of the inspiration loop. The expiration loop comprises a check valve, an expiration flow meter, a novel expiration valve and a water-removing bottle, which are connected successively. The breathing mask is internally provided with a carbon dioxide concentration sensor. The carbon dioxide concentration sensor, the pressure sensor A, the intelligent air-oxygen mixer, the inspiration flow meter and the expiration flow meter are connected with an ARM processor. The ARM processor is connected with an LED touch screen and an alarm. The medical intelligent ventilator can work according to the autonomous respiration of a patient, can maintain positive end-expiratory pressure of a patient, can discharge gas exhaled by a patient, is safer and can give alarm automatically.