Hard rock drilling rig with good stability

The utility model discloses a drilling rig for hard rock with good stability, which comprises a base, four upright posts welded on the top surface of the base, a first mounting plate and a second mounting plate sleeved on the upright posts, a motor fixed on the bottom surface of the first mounting plate, a connecting shaft connected with the motor, and a square limiting plate arranged at the bottom end of the connecting shaft. The square limiting plate is connected with a rock core pipe through an elastic buffer structure, a limiting clamping groove is formed in the square limiting plate opposite to the connecting part, an elastic damping block is arranged in the limiting clamping groove, a detachable drill bit is arranged at the bottom end of the rock core pipe, and a top plate and a telescopic air cylinder are fixed to the top end of the stand column. The device has the beneficial effects that in the process that pressure and vibration borne by the rock core pipe are transmitted to the motor, buffering and