The utility model provides an automatic feeding and discharging device of a gear hobbing machine additionally provided with a truss type mechanical arm. Gear hobbing machine, a vibrating disk feedingdevice is arranged on the rear side of the gear hobbing machine; the lower end of the vibration disc feeding device is provided with a vertically-arranged material placing mechanical arm device. According to the automatic feeding device of the gear hobbing machine, the vibrating disk feeding device is used for feeding, the material distributing air cylinder is used for isolating products, the feeding transition switching device is used for taking away workpieces from the linear vibrator, and the automatic feeding device of the gear hobbing machine is matched with the gear hobbing machine mechanical arm device for feeding. The gear hobbing machine mechanical arm device takes materials, sends the workpieces into the gear hobbing machine for standby, the gear hobbing machine machines the workpieces, the deburring device removes burrs of the products, and during machining of the gear hobbing machine, the gear hobbing machine mechanical arm device sends finished products to the transition workpiece posture adjusting device. The material placing mechanical arm device is responsible for placing materials, and discharging is conducted after placing is completed.