Low-clearance rotary drilling rig

The invention relates to a low-clearance rotary drilling rig and belongs to the technical field of rotary drilling rigs, the low-clearance rotary drilling rig comprises a platform, a mast mounted on the platform, a power head fixed on the mast and a drill rod connected with the power head, a drill bit is mounted at the bottom of the drill rod, and the mast comprises a mounting section and a limiting section which are hinged to each other and locked through a bolt. The mounting section is arranged close to the platform, the power head is fixed on the mounting section, the limiting section is rotationally connected with the platform, and a limiting rod for controlling the perpendicularity of the mounting section is mounted between the mounting section and the platform. During drilling, the mounting section and the limiting section are fixed into a straight line, and then the limiting rod is mounted between the mounting section and the power head, so that a drill rod penetrating through the interior of the power