The invention discloses a hydraulic cylinder with variable sections. The hydraulic cylinder comprises a piston rod, a cylinder barrel, a left end cover and a right end cover, wherein the left end cover and the right end cover are used for sealing the cylinder barrel; the piston rod comprises a main piston rod and plunger rods; the main piston rod is hermetically mounted on the cylinder barrel through the left end cover and the right end cover; a main piston is arranged at the end part of the main piston rod; a plurality of plunger rods are mounted on the main piston; secondary pistons are arranged at the end parts of the plunger rods; the main piston is mounted in the main piston cavity which is in the cylinder barrel and corresponds to the main piston; the secondary pistons are mounted in the plunger cavities which are in the cylinder barrel and correspond to the secondary pistons. The hydraulic cylinder has a certain capacity of load matching, and is a linear hydraulic cylinder capable of improving the efficiency of a hydraulic system with variable loads. When the hydraulic cylinder is under a loading condition with variable loads, a user can select different small cavities to be communicated with a high-pressure oil circuit or a low-pressure oil circuit to realize load matching so as to finally achieve the purpose of improving the efficiency of the hydraulic system.