Multi-level piston two-way hydraulic cylinder

The invention relates to a multi-level piston two-way hydraulic cylinder comprising a cylinder body, wherein the cylinder body comprises a fixed cylinder body and movable cylinder bodies not less than one level; the cylinder body of each level is internally provided with a piston; an uplink cavity is arranged below each piston, and a reverse cavity is arranged above each piston; the lower end of the piston rod is fixed with the piston inside the last-level movable cylinder body together or integrated with the piston inside the last-level movable cylinder body into a whole; the lower end of the last-level movable cylinder body is fixed with the piston inside the next-level movable cylinder body together or integrated with the piston inside the next-level movable cylinder body into a whole and is provided with an uplink oil way on the piston to communicate the uplink cavities of the last-level movable cylinder body and the next-level movable cylinder body; the movable cylinder bodies are provided with reverse oil passages, and upper inlets and upper outlets of the reverse oil passages are communicated with the upper part of the reverse cavities inside the movable cylinder bodies. The invention has reasonable and compact structure, solves the problem that the piston rod of the traditional hydraulic cylinder is limited in extending distance and has slower extending or contracting speed, and can realize the long extending distance and the fast extension or contraction of the piston rod, thereby enhancing the applicability and the performance of the hydraulic cylinder.