When the engine block is in service, there will be external dust particles accompanied by diesel and gasoline into the cylinder block, wear and corrosion damage the surface of the engine block, affecting the performance of the engine. In order to repair the cylinder body surface, a wide-band laser cladding head with output spot size of 15 mm×3 mm was used to repair the engine cylinder body surface by single-channel wide-band laser cladding experiment. The cladding base material is 42CrMo steel, and the cladding powder material is Fe316L. The influence of parameters, such as laser power, powder feeding speed, air flow and scanning speed, on the cladding quality and the weight of each parameter are studied, and when the best process parameters are obtained as laser power 4 250 W, powder feeding speed 3 r/min, and air flow 5.1 L/min and scanning speed of 459 r/min and cladding at the focal point, the cladding quality is higher. The surface roughness of the cladding layer is 2.19 μm, and the microhardness of the cladding layer is 552.9 HV.