An air turbo-starter air supplying system comprises an air inlet pipeline, one end of the air inlet pipeline is connected to an air tank, and the other end of the air inlet pipeline is divided into an air supply pipeline and an air exhaust pipeline. The air inlet pipeline is provided with a first electromagnetic valve, the rear end of the first electromagnetic valve is connected with a pressure regulating valve, and a second electromagnetic valve is arranged on the air supply pipeline. The tail end of the air supply pipeline is connected with a starter. A normally open electromagnetic valve is arranged between the starter and the second electromagnetic valve. The normally open electromagnetic valve and the second electromagnetic valve share the same control switch. A third electromagnetic valve is arranged on the air exhaust pipeline, and the tail end of the air exhaust pipeline is connected to an equivalent nozzle. When the second electromagnetic valve is opened, the normally open electromagnetic valve is closed, and air supplying of the air supply pipeline to the starter cannot be affected. When the second electromagnetic valve is blacked out and closed, the normally open electromagnetic valve is open, air in the air supply pipeline is exhausted, it is guaranteed that the inlet pressure of the starter is started is zero when the air turbo-starter air supplying system, and therefore the inlet pressure of the starter is reduced, the clutch breakage caused by high-pressure shock is avoided, and the maintenance cost for the air turbine starter is saved.