Abstract: In order to solve the problems of lower relative density and bad mechanical property of metal parts manufactured by Selective Laser Sintering (SLS), the characteristics of the selective laser sintering were analyzed briefly first, then the effect of the scan path upon metal forming was discussed in detail,and finally the mechanism of the laser sintering metallic powders was explored preliminarily. Ni-based F105Fe alloy powders parts were manufactured via SLS. According to scanning electron microscope (SEM), micro-hardness testing machine and archimedes law etc,the influence of scanning path on microstructure, micro-hardness and relative density of SLS samples were analyzed. The results show that different scanning paths have no influence on microstructure but will affect the homogenization and refinement especially for mechanical property. The parts which manufactured by scanning path with direction shift have high hardness and greatest relative density while the parts manufactured by scanning path with the same direction have the best microhardness.