The piston rod of the bucket cylinder may be bent and deformed during the use of the excavator. Sometimes the piston rod on one side is bent. There are many reasons for the bending of the bucket piston rod. The first is the piston rod itself. For example, the bolts are loose and fall off, and the materials used are not qualified. Secondly, the bucket piston rod is impacted by external force. Generally, the fastening bolt of the pin shaft of the unilateral bucket link falls off, resulting in the change of the position of the oil cylinder, and the deformation of the bucket caused by jacking the bucket during the use of the bucket. In daily inspection, failures caused by loose screws can be avoided. As long as the bucket cylinder and bucket link are replaced and the locking bolts and nuts of each pin shaft are tightened, the normal use can be resumed.