The utility model discloses an oil cylinder piston rod with a rod measuring function. The oil cylinder piston rod comprises an oil cylinder piston rod body. A plurality of annular grooves are formed in the oil cylinder piston rod at equal intervals along the length direction. Two kinds of materials with different magnetic conductivity are inlaid in the annular grooves in a spaced mode. One kind of materials of the two kinds of materials with the different magnetic conductivity are non-permeability magnetic materials. The non-permeability magnetic materials are made of copper. The permeability magnetic materials are made of 45# forged steel. According to the oil cylinder piston rod, the two kinds of materials with the different magnetic conductivity are divided, arranged and used on the piston rod at equal intervals, changes of open-close-open-close...of magnetic flux in unit time are detected and inducted by an electric magnet ring in the motion of the piston rod, displacement distance of an oil cylinder piston is obtained through electronic signal analysis and routine calculation, and purposes of route measurement and route control of an oil cylinder with a minor diameter are achieved.