A switching device for a pneumatic tool includes a valve member, a connecting member and an operating unit. The valve member is rotatable relative to the pneumatic tool between first and second positions. The connecting member is coupled to the valve member in a manner such that the connecting member drives the rotation of the valve member and that an assembly of the valve member and the connecting member is flexible, so as to establish an air-tight seal between the valve member and a pneumatic motor of the pneumatic tool. The operating unit is mounted on the pneumatic tool and coupled co-rotatably to the connecting member.