A method for purifying polluted air having particle phase pollutants and gaseous phase pollutants is provided. The method comprising: separately purifying and treating particle phase and gaseous phase pollutants present in the air; providing a dust cleaning apparatus, a catalytic filter core and a valve for controlling an airflow path within an air purification apparatus; controlling the airflow path for the air to bypass the catalytic filter core in a way that: if the amount of particle phase pollutants is above a predetermined value, the valve is moved to the open position to enable the air to bypass the catalyst filtering core; if the amount of particle phase pollutants is less than a predetermined value, the valve is moved to the closed position to force the air to pass through the catalyst filtering core.