For energy saving and longer life time of a large casting iron may use of weld repairs or make up to more save manufacture time and energy than re-casting. Such as breakage, crack and wear in large casting iron castings used weld to repair casting for eco-energy. The purpose of this study is to investigate the dissimilar joint property of S45C carbon steel with the multi-layer method and the multi-pass welding method. Four weld rods, experimentally examined the influence on microstructures, which were marked as A, B, C and D, respectively. The microstructures of joint bead were observed by the optical microscope. The specimens of tensile test were made according to ASTM E8M. The experimental results were shown as following: 1. The pearlite structures and the bainite structures were formed in welded zone by the weld rod of middle carbon steels. The yield strength and ultimate strength of the specimens were 360MPa and 460MPa. 2. The feature of welded specimen was close to stainless steel due to the stainless steel rod included some Cr and Ni. In addition, a ferritic-austenitic two-phase stainless steel was observed in optical microscope.