Effects of nanosecond pulsed fiber laser surface remelting on the microstructure, mechanical properties, and wear-resistance of 316L stainless steel were investigated. Three-dimensional laser scanning confocal microscopy, optical microscopy, and scanning electron microscopy were used to characterize the surface morphologies, microstructures, tensile fracture morphologies, and wear morphologies of the stainless steel before and after remelting. The results show that the remelting layer can be divided into a planar crystal zone, a dendrite growth zone, and an isometric zone from the bottom to the surface. Laser remelting can increase the tensile strength of 316L stainless steel from 580 MPa to 710 MPa, significantly increasing the microhardness and wear resistance of the stainless steel.