The invention relates to a full-hydraulic impact core drilling rig mechanical clutch power output device. According to the full-hydraulic impact core drilling rig mechanical clutch power output device, different torques and rotation speeds can be outputted stably with the same drilling rig, and drilling technique requirements of different strata can be satisfied, and maintenance frequency can be reduced. The full-hydraulic impact core drilling rig mechanical clutch power output device comprises a main drive shaft which is in drive connection with a diesel engine power output disc. The full-hydraulic impact core drilling rig mechanical clutch power output device is characterized in that a main drive gear is fixedly installed on the main drive shaft; two sides of the main drive shaft are provided with a first oil pump driving shaft and a second oil pump driving shaft respectively which are parallel to the axis of the main drive shaft; and the first oil pump driving shaft and the second oil pump driving shaft are respectively provided with a gear clutch drive device which is in drive connection with the main drive gear.