A pneumatic turbine motor air chamber drives a pneumatic turbine to rotate through compressed air. The pneumatic turbine has a ring extended from inside thereof that has a plurality of barriers and forms a housing space to hold a speed regulator. The pneumatic turbine also has an air intake coupling hole leading to the housing space and at least one air discharge vent communicating with an air passage to discharge the compressed air. The ring is integrally formed with the pneumatic turbine to enhance operation steadiness of the pneumatic turbine.