Abstract: In this paper,the laser hardening technological parameters and the nigrescence technology with surface oxidation have been studied on tiny workpieces of 4Cr13 stainless steel,while the influences of the laser technology and various lapping ratios on hardness,depth and microstructures of the hardening layer have been explored. The results show that the surface of Φ10mm×8mm workpieces can be hardened by means of proper laser technology,meanwhile,an uniform hardened layer can be achieved with surface hardness of 42 HRC～45HRC at 40 percent lapping ratio,which can meet the designed requirement.