The boronizing layers of 45 steel of drilling pump liner have been remelted with laser, and the wear resistance properties, phase transition and microstructures of the boronizing layers before and after laser remelting were analyzed. The results show that laser remelting enhances surface abrasive wear resistance properties by 40% ~90%. Laser remelting achieves improvements mostly by means of alternating boronizing layer morphologies, eliminating FeB and defects within boronizing layer, improving the interface bonding intensity, fining the microstructures, redistributing boron concentration and generating lots of alloy phases. The strong support to material surfaces by martensites gained during remelting process within transition area is also beneficial to improve wear resistance properties. It is shown from the practice that the laser remelting compound technology followed boronizing shall be widely used in surface hardening of petrochemical key parts.