Used in the hydraulic system of various kinds of compressed garbage trucks, the GL series compressed garbage truck hydraulic cylinders include pushing cylinder, sliding cylinder, scraping cylinder and lifting cylinder. The pushing cylinder, the most special one among those, is a double-action telescopic hydraulic cylinder with inlet and outlet ports on the rod end. The special piston seal has been adopted through oil port in cylinder and to reduce the inter-leakge in the piston seal system. The sliding cylinder, scraping cylinder and lifting cylinder look like the HSG hydraulic cylinder model 1301. Some of the lifting cylinders are plunger piston cylinder. Its features are reasonable in structure, reliable in operation and convenient in assembly and disassembly, easy in maintenance. The special designs are also available according to the user requirements and specific technical parameters. A hydraulic lock valve may be installed on the cylinder head if required.