The utility model relates to a stroke adjustable hydraulic cylinder used for adjusting the stroke after long-time working of a plurality of equipments in all industries. The utility model consists of a cylinder bottom, a cylinder body, a cylinder head, a piston and a piston rod; the utility model is characterized in that the tail extended end of the piston rod is fixedly provided with a retaining block which is a round structure; the external round of the retaining block is provided with 12 equal graduations; meanwhile, the external end surface of the cylinder bottom is also provided with a 12 equal part dial. When the stroke of the piston is required to be adjusted, the retaining block is rotated according to the dial by corresponding angles before fixed by a locking bolt. The utility model has the advantages of reasonable design, simple structure, adjusting the speed and the stroke, safe operation, convenient application, economy and practicability, etc.