The work aims to reduce the deformation of the substrate during laser cladding repair of thin-wall parts, and im-prove the forming quality. On the basis of previous single channel and single factor test, Fe1 alloy powder was cladded on 2 mm thick 45 steel by three factors and three level orthogonal test, and the influences of laser power, scanning speed and powder feeding rate on the deformation behavior of sheet metal were analyzed. According to the factor effect diagram, the changes of the substrate deformation along with the factors level were also investigated and the corresponding reason was found out. The formula of the deformation of the substrate was put forward by the extreme analysis of the orthogonal test. According to the formula, the main and secondary relation of the influence on the substrate deformation caused by the factors was determined, and the optimum process parameters to minimize the substrate deformation were finally found out according to the deformation results. The microstructure and hardness of the cladding layer under the optimal process parameters were studied by optical mi?croscope (OM), scanning electron microscope (SEM) and microhardness tester, and the molding quality of the cladding layer under the optimal process parameters was evaluated. The factors affecting the substrate deformation were laser power, scanning speed and powder feeding rate in order. The optimal process parameters to minimize the substrate deformation and realize good metallurgical bonding were 600 W laser power, 12 mm/s scanning speed and 1.2 r/min powder feeding rate. The maximum hardness of the cladding layer under such process was 348HV (about 1.6 times of the substrate hardness). The process parameters can effectively reduce the substrate deformation, ensure the good laser cladding quality and strengthen the substrate surface significantly.