The utility model discloses a hydraulic drive rotary drilling device for a hydraulic shovel. The hydraulic drive rotary drilling device for the hydraulic shovel comprises a connecting mechanism, a driving mechanism, a transmission mechanism and a rotary drilling head. The connecting mechanism is a sleeve barrel connected with a bucket rod of the excavator, and the driving mechanism is a hydraulic motor placed inside the sleeve barrel. An oil-way of the hydraulic motor is added with a reversing valve and is connected with a hydraulic oil-way of the shovel, and the transmission mechanism is a reducer driven by the hydraulic motor. The rotary drilling head comprises a rotary excavator bucket connected with the reducer, a door sheet used for opening and closing a lower opening of the rotary excavator bucket and a door sheet opening and closing mechanism controlling the open and closure of the door sheet according to the direction of the turning of the rotary drilling head. The rotary drilling device with the structure can be matched with the hydraulic shovel to use, the current situation of long-time digging job depending on manual labor is shaken off, and a low-cost mechanizing digging job is achieved.