The utility model discloses a move flexible isolated form oil well lift cylinder of rod -type, including the hydro -cylinder body, the hydro -cylinder body includes and still includes piston rod isolation protection device by the piston rod, during the piston rod stretched into piston rod isolation protection device, lower end of the piston rod connected the inside bottom of piston rod isolation protection device, piston rod isolation protection device is telescopic isolating barrel, telescopic isolating barrel includes at least two -stage isolating barrel, and isolating barrel is sealed for the slidingtype between two liang. Isolating barrel all sets up the anticreep from keeping off the platform. Landing leg formula support is connected to the cylinder bottom. Telescopic isolating barrelfixes in landing leg formula support bottom the upper end. Landing leg formula support passes through the flange joint seat and adorns in oil well wellhead. The utility model discloses keeping aparthydraulic oil and well liquid completely, thoroughly eliminating hydraulic system's pollution, assurance hydraulic pressure oil pumping system reliably works the long -life.