The invention relates to a buffering sleeve, a working cylinder of a hydraulic device and a hydraulic operating mechanism. The working cylinder of the hydraulic device comprises a cylinder body, a piston and the buffering sleeve; a blocking step is arranged on the inner wall of the end, corresponding to the tail end of a buffering stroke of the piston, of a piston cavity, and a plug is arranged at the end head of the end; the buffering sleeve is movably arranged between the blocking step and the plug in the axial direction of the cylinder body, an inner hole for allowing a buffering shaft of the piston to be inserted therein is formed in the buffering sleeve, and an oil passing hole penetrating through the buffering sleeve in the axial direction is further formed in the buffering sleeve; a center hole is formed in the center of the plug, and the plug is provided with a blocking end face for blocking the oil passing hole in the buffering sleeve when in blocking matching with the buffering sleeve; and an oil passing groove is formed in the outer side wall of the buffering sleeve, openings are formed in the two end surfaces of the buffering sleeve correspondingly through the oil passing groove, the opening in the end, away from the plug, of the oil passing groove is in communication with the piston cavity, the opening in the other end of the oil passing groove is blocked by the blocking end face of the plug when the buffering sleeve and the plug are in blocking matching, so that the starting speed of the working cylinder of the hydraulic device is increased.