Fe-Cr-Mo-Si alloy powder was added to the surface of Q235 steel to prepare a wear-resistant iron-based cladding layer by using 3 kW fiber-coaxial laser cladding equipment. The Fe-Cr-Mo-Si cladding layer's microstructure, hardness, and friction-wear behavior were studied using a metallographic microscope, Vickers hardness tester, and friction and wear testing machine. The results show that the microstructure of the Fe-Cr-Mo-Si cladding layer is uniform and dense without pores, cracks, and other defects. The cladding layer is composed of dendritic crystals. A fine planar crystal structure is formed at the bonding surface of the cladding layer and Q235 steel, and the cladding layer and the substrate exhibit good metallurgical bonding. The average hardness of the cladding layer reaches 642.2 HV, which is four times the substrate's hardness. When the load is 50 N, the average friction coefficients of the cladding layer and the substrate are 0.621 and 0.512, respectively, and the wear mass loss of the cladding layer is 14.6% of the substrate. The friction coefficient decreases as load increases, whereas the size of the wear outline increases as load increases. The results show that the wear mechanism of the cladding layer is abrasive wear and adhesive wear, while that of the substrate is mainly adhesive wear and fatigue spalling wear. The laser cladding of Fe-Cr-Mo-Si alloy powder on Q235 steel can improve wear resistance significantly.