Reversible mechanical paws are characterized by including a swinging base, a transmission shaft and a mechanical paw connecting plate, wherein the transmission shaft is horizontally installed in an axle hole of the swinging base through a bearing support, the mechanical paw connecting plate is vertically installed above the swinging base through connecting pieces and used for connecting with a mechanical arm. One end of the transmission shaft is combined with the mechanical paw through a connecting key, and the other end of the transmission shaft is combined with a swing hydraulic cylinder through a gear transmission mechanism. The mechanical paws comprise a fixed paw connected with a transmission shaft key and a movable paw hinged to the fixed paw through a hinge pin, and the fixed paw and the movable paw jointly form a U-shaped mechanical paw structure approximately. The hinged end of the fixed paw and the movable paw is provided with a clamping hydraulic cylinder used for driving the movable paw to open or clamp. A group of clamping blocks are arranged on one side of a clamping working face of the movable paw, two groups of clamping blocks are arranged on one side of a clamping working face of the fixed paw, and the three groups of the clamping blocks are formed into a triangle-shaped arrangement like a Chinese character 'Pin'.