The invention relates to a plug pin type safety device for a hydraulic machine, which is characterized by mainly comprising a support frame, a cover plate, a safety bolt and an air cylinder, wherein the support frame is fixedly arranged on the side wall of an upright post of the hydraulic machine, the cover plate is fixedly arranged at the outer side of the support frame, a rectangular groove is formed by the cover plate and the support frame, a plug pin plate is arranged in the rectangular groove and is connected with a piston rod of the air cylinder, the air cylinder is fixedly arranged on the cover plate, the end part of the plug pin plate is provided with an installing hole, the safety bolt is arranged in the installing hole in a penetrating way, a support spring is sheathed on the safety bolt, the lower end of the support spring is seated and arranged on the plug pin plate, a position limiting ring is arranged on the safety bolt, and a guide device is arranged between the plug pin plate arranged in the rectangular groove and the inner wall of the rectangular groove. Compared with the prior art, the plug pin type safety device has the advantages that the structure is simple, the installation and the use are convenient, in addition, the occupied space is small, the maintenance is easy, the safety performance is high, and the like.