A Fe-based amorphous composite coating was deposited on a carbon steel substrate by arc spraying, and remelted with different laser energies by the Nd: YAG laser cladding system, in order to improve the mechanical properties of the coatings. The microstructure and microhardness of the composite coatings were investigated. The variation of harndness was measured as a function of the modified layer depth, which indicates that the laser remelting improves the bonding strength and hardness. Increasing the laser power, the quality of coating gets better, but the amorphous volume fraction decreases. It is obtained that the optimal laser electric current for the coating of 280 μm thickness is about 300 A, in which the remelted coating with medium energy densities has the highest average Vickers hardness of 741. Through the volume fraction change of the nanocrytals, the hardness of the composite coating is regulated by the laser power input, which amplified the application fields of the amorphous coatings.