A disassembling device for removing fastening components embedded in a workpiece includes a supporting base, a clamping assembly, and a pushing assembly. The pushing assembly includes a sliding assembly, an adjusting rod, and an ejecting pin. The workpiece defines a first through hole which communicates with a positioning hole. The workpiece is clamped by the clamping assembly, the sliding assembly is connected to the supporting base and can slide along a first direction and a second direction perpendicular to the first direction. The adjusting rod passes through the sliding assembly to connect with the ejecting pin, the ejecting pin is driven to extend into the first through hole and to move in a direction perpendicular to the first and second directions, so as to push the fastening component out of the positioning hole.