A ventilation therapy apparatus, comprising: a main body, a respiratory pipe, a patient interface, an oxygen supply module, an oxygen proportional valve and a control module; wherein, the main body is configured for outputting gas with a preset pressure and a preset flow, and the main body comprises an output end; the respiratory pipe comprises a first end and a second end which communicates with each other, and the first end of the respiratory pipe communicates with the output end; the second end of the respiratory pipe is connected to the patient interface, the patient interface is configured for being worn on a patient's nasal cavity, and when the patient interface is worn on the patient's nasal cavity, an air outlet gap is disposed between the patient interface and the patient's nasal cavity; the oxygen supply module is connected to the main body through the oxygen proportional valve, and a fan is disposed in the main body; the main body is configured to mix an inhaled air with the oxygen provided by the oxygen supply module, and output a gas mixture through the respiratory pipe; the control module is connected to the main body and the oxygen proportional valve, respectively; and the control module is configured for detecting output parameters of the main body, the output parameters comprising an airflow pressure and an air flow at the output end of the main body, when it is determined that the main body is in a preset state, the control module, according to the output parameters, is configured to: control the oxygen proportional valve to open at a corresponding preset opening degree, and control the fan of the main body to run at a corresponding preset rotating speed. the main body is configured for outputting gas with a preset pressure and a preset flow, and the main body comprises an output end; the respiratory pipe comprises a first end and a second end which communicates with each other, and the first end of the respiratory pipe communicates with the output end; the second end of the respiratory pipe is connected to the patient interface, the patient interface is configured for being worn on a patient's nasal cavity, and when the patient interface is worn on the patient's nasal cavity, an air outlet gap is disposed between the patient interface and the patient's nasal cavity; the oxygen supply module is connected to the main body through the oxygen proportional valve, and a fan is disposed in the main body; the main body is configured to mix an inhaled air with the oxygen provided by the oxygen supply module, and output a gas mixture through the respiratory pipe; the control module is connected to the main body and the oxygen proportional valve, respectively; and the control module is configured for detecting output parameters of the main body, the output parameters comprising an airflow pressure and an air flow at the output end of the main body, when it is determined that the main body is in a preset state, the control module, according to the output parameters, is configured to: control the oxygen proportional valve to open at a corresponding preset opening degree, and control the fan of the main body to run at a corresponding preset rotating speed. control the oxygen proportional valve to open at a corresponding preset opening degree, and control the fan of the main body to run at a corresponding preset rotating speed.