The KGH5AⅢdown the hole drill rig for open use is an improved device in compliance with national regulations on environmental protection. Equipped with the Yuchai four-cylinder engine, the drill rig meets the national standards for emissions and environment. The flexible derricking mechanism is suitably qualified for horizontal drilling at a low level. The hydraulic system has been improved, leading to increased system flow and rotary speed. Moreover, the hydraulic cylinder has been optimized, thus making it more reliable; and the additional ring (plate) makes handling and lifting easier.