A crank-type drive device for a loom including a crank hub non-rotatably attached to a drive shaft, a holder non-rotatably attached to the crank hub, an eccentric shaft supported by the holder, and a connecting member rotatably supported by the holder via the eccentric shaft and a bearing and connected to a drive target member of a loom. The crank hub includes a plate-shaped attaching part which an attached surface of the holder is attached thereto and has an attaching surface in contact with the attached surface, and a fixing mechanism for fixing the crank hub to the drive shaft, the drive shaft being inserted and fitted in the fixing mechanism. The crank hub is configured so that the fixing mechanism is positioned on the attaching surface-side of the attaching part in a plate thickness direction.