Hydraulic cylinder bars are mainly used in hydraulic and pneumatic, engineering machinery, and piston rods for automobile manufacturing. The piston rod is processed by rolling, and the residual stress on the surface layer is left to help the surface of the surface crack, which hinders the expansion of the erosion. Thereby, the surface corrosion resistance is improved, and the generation or expansion of the fatigue crack can be delayed, thereby improving the fatigue strength of the cylinder rod. By rolling forming, the rolling surface forms a cold hardening layer, which reduces the elastic and plastic deformation of the grinding contact surface, thereby improving the wear resistance of the cylinder rod surface and avoiding burns caused by grinding. After rolling, the surface roughness value is reduced to improve the compounding property. At the same time, the friction damage to the sealing ring or the sealing member during the movement of the cylinder rod piston is reduced, and the overall service life of the oil cylinder is improved.