The invention discloses a multistage hydraulic cylinder. The multistage hydraulic cylinder comprises a cylinder barrel, a first piston, a second piston and a third piston, wherein the first piston issleeved in the second piston; the second piston is sleeved in the first piston; the third piston is sleeved in the second piston; clamping frames are arranged on the upper surface of the third piston,and are symmetrically distributed at the upper end of the third piston; fixing devices are arranged on the cylinder barrel, and are symmetrically distributed on the surface of the cylinder barrel; and an oil outlet pipe and an oil inlet pipe are arranged on the cylinder barrel. The multistage hydraulic cylinder is simple in structure, longer in transmission stance, free of transmission gaps and stable in movement.