The invention discloses a terrestrial heat drilling device and a using method, and relates to the technical field of terrestrial heat drilling, the terrestrial heat drilling device comprises a base, a
workbench, a lifting piece, a driving piece, a quick connector, a
drill rod and a
drill bit, and is used for achieving drilling actions; a receding hole is formed in the middle of the base, a locking device is arranged on the
peripheral side of the top of the receding hole, and a pressure adjusting sealing cavity is formed in the locking device and used for adjusting the torque resistance value when the locking device locks the
drill rod; a force unloading
assembly is rotationally arranged on the inner side of the clamping face of the locking device in the extending direction of the locking device, the pressure adjusting sealing cavity is used for providing rotating anti-torsion force for the force unloading
assembly, and when the rotating torsion value of the drill rod under the action of the driving piece is larger than or equal to the anti-torsion
value set by the locking device, the force unloading
assembly automatically rotates to unload force. Damage to connecting threads or unstable connection caused by too large or too small rotating torsion of the drill rod is avoided; an auxiliary rod feeding device is further arranged on the side face of the base and used for conducting automatic transferring and
butt joint on the drill rods, and the efficiency and safety of geothermal drilling operation are improved.