The invention relates to a drilling device and belongs to the field of processing devices. The drilling device comprises a machine tool, a servo motor, a clamping device and a drilling device, wherein the clamping device and the drilling device are arranged on a horizontal sliding rail; the drilling device comprises a drill bit holding cavity; a drill bit adjusting module and a plurality of different types of drill bits are arranged in the drill bit holding cavity; each drill bit is connected to the servo motor through a driving device; the servo motor is connected to the drill bit adjusting module. By aiming at the technical problems that the labor cost is increased and the processing efficiency is reduced caused because the workpieces to be processed are manually controlled mostly to be separately processed among a plurality of drilling devices when a plurality of different types of holes are required to be drilled in the workpieces in the prior art, the invention provides a drilling device which comprises a drill bit adjusting module used for adjusting and selecting drill bits and a plurality of optional different types of drill bits; the technical effect of carrying out operation of processing different types of drill holes by just switching the drill bits without need of manually moving the workpieces to be processed can be achieved.