The invention provides a downward-turning type passenger car safety escape window. After the car window is unlocked, a car window body is ejected out through an ejection mechanism, and then the car window body is pushed downwards and opened in a pneumatic driving mode. Gas required for pneumatic driving is from an internal air source and an air storage tank of a passenger car, under the emergencycondition, an initial driving air pressure is provided by the internal air source of the passenger car, the insufficient part is supplied by the air storage tank, and enough driving force can be provided for opening the safety escape window through the pneumatic driving mode, so that all the safety escape windows can be opened under the conditions of the damaged window body, foreign object extrusion and the like. In addition, when the safety escape window is opened, a mode that the safety escape window is opened in the outward direction and then moves downwards is adopted, an opened safety escape window structure can be taken as an armrest, support is provided for passengers for escape, the armrest can assist the passengers in the passenger car with escaping, and secondary injury in the escape process is effectively avoided; and compared with an existing outward-turning mode, the window opening space is larger.