The invention relates to a special device and a method for fishing a drill bit of a rotary drilling rig in case of drilling blocking. The special device is characterized by comprising a support device, a power control device and a clamp traction device, wherein the support device comprises a pair of rectangular steel base plates, four hydraulic jacks and one frame-shaped shoulder pole; the pair of rectangular steel base plates are arranged on two sides of a drilling hole in a parallel and symmetric manner; the hydraulic jacks are respectively arranged at end parts of the rectangular steel base plates; four corners of the frame-shaped shoulder pole are correspondingly arranged on the four hydraulic jacks; the power control device comprises an oil pump; an oil pump control valve is arranged on the oil pump; the oil pump control valve is connected with the four hydraulic jacks; the clamp traction device comprises a frame-shaped steel buckle clamp; the frame-shaped steel buckle clamp consists of a left half steel buckle and a right half steel buckle; steel wire ropes are arranged at four corners of the frame-shaped steel buckle clamp; the steel wire ropes are connected with the frame-shaped shoulder pole. The special device is simple in structure and can be assembled and used on site, and the drill bit can be safely and effectively taken out once the drill bit of the rotary drilling rig is blocked.