Abstract: In order to improve the lubrication of movement mechanism in final optics assembly, the plasma immersion ion implantation (PIII) technology is used to modify mechanical properties of work pieces with complex shape. The combination of suitable parameters can largely increase the hardness and wear resistance of material surfaces. The verification test was made by modifying the mechanical properties of the bearing inner race and bearing outer ring. Furthermore, the dimensional accuracy and the surface roughness of sample work pieces modified by PIII technology can maintain consistence with those of untreated pieces. The work sufficiently certificates that the PIII technology can amend the mechanical properties of work pieces and elongate the life length of movement mechanism kinematic accuracy.