The invention provides a drilling device and belongs to the field of processing devices. The drilling device comprises a machine tool, a drilling device, a clamping device and an overturning device used for overturning workpieces, wherein a horizontal sliding rail is arranged on the machine tool; the drilling device and the overturning device are arranged on the horizontal sliding rail; the overturning device comprises a first support rod, a first motor and a first overturning shaft; the first support rod is connected with the horizontal sliding rail in a sliding manner; the first overturning shaft is arranged at the top end of the first support rod; the first overturning shaft is connected with a rotation shaft of the first motor in a transmission manner; the other end of the first overturning shaft is connected with the clamping device. Through the drilling device, the technical problem that the double-sides processing is carried out by manually overturning the workpieces mostly in the prior art can be avoided; the technical effects of improving working efficiency and saving labor cost can be achieved.