The technique of laser surface remelting was carried out at different power parameters on an A356 aluminum alloy surface to analyze the microstructure and microhardness of the remelting layer. A three-point bending test was then used to study the mechanical properties of the remelting layer as well as the bonding properties between the layer and the substrate. Compared with that of the substrate, we found the microhardness of the remelting layer greatly increased. Regarding other properties, both the fine grain strengthening and second phase dispersion strengthening are found to increase the strength of the remelting layer, which delays the appearance of the initial cracks in remelting layer. The remelting layer and substrate had good metallurgical bonding ability and no cracks appear at the interface. The remelting samples also show favorable surface mechanical properties with no delamination appearing between the remelting layer obtained at laser power of 1500 W or 2000 W and the substrate.