The utility model discloses a compact and precise guide cylinder, which comprises a guide block, a cylinder fixed on the guide block, and guide rods arranged on two sides of the guide block, the guide block is arranged between the two guide rods, a
fastener is arranged at the position of the guide block deviating from the cylinder, the
fastener is fixedly connected with the guide block through a first nut, and the first nut is connected with the guide block through a second nut. The
fastener is in threaded connection with a
piston rod of the air cylinder, a sinking groove with an opening is formed in one side of the guide block, and the
piston rod of the air cylinder penetrates through the sinking groove. Through the arrangement of the sinking groove with the opening, a maintainer can make contact with and act on the nut rapidly and conveniently through a tool, so that disassembly operation is efficiently executed, the air cylinder replacement speed is effectively increased, and the equipment shutdown time is shortened; when the guide rod ascends and descends, the lubricating
assembly synchronously moves along with the guide rod, so that lubricating oil stored in the lubricating
assembly is evenly smeared to the surface of the guide rod, the friction resistance between the guide rod and the guide block is reduced, and the service life of parts is prolonged.