The utility model discloses a guan yiyun instrument is grabbed to hydraulic pressure, including the crossbeam, there is the roating seat at crossbeam intermediate position fixed mounting, the roating seat excircle passes through slide bearing and fixing base suit, and fixed surface is connected with the flange on the fixing base, and surface mounting has the engaging lug seat on the flange, fixed surface installs hydraulic motor under the fixing base, and hydraulic motor's output shaft passes through clamp plate and pinion coaxial coupling, and the pinion is connected with the large gear transmission, and the fixed suit of gear wheel is on the roating seat excircle, along having welded an otic placode respectively under the both ends of crossbeam, it has an otic placode to follow welding respectively outside the head of the both ends of crossbeam, and the otic placode on every limit is held through a round pin axle and a hydraulic cylinder's cylinder and is connected, and tailpiece of the piston rod and a lifting hook middle part of this hydraulic cylinder are connected, and this lifting hook upper portion is connected with the otic placode of this side through a round pin axle. The utility model discloses a device, positioning adjustment is simple, and the centre gripping moves fortune steadily, and the security is good.