Remanufacturing system is a term of green system project which conforms to the national sustainable development strategy. With the demand of the high adaptability of the varieties of waste machining parts, the short product cycle, the low machining cost and the high product quality are offered. Each step of the remanufacturing system from the beginning of the scanning to the accomplishment of the welding was investigted. Aiming at building a remanufacturing system based on totally automatic MIG surfacing via robot, advanced information technology, remanufacturing technology and management, through the control of the pretreatment and the optimization to minimize the time of remanufacturing and realize the remanufacturing on the terminal products of varieties, were applied. The steps mainly include: 1) using the visual sensor which is installed at the end of the Robot to rapidly get the outline data of the machining part and the pretreatment of the data; 2) rebuilding the curved surface based on the outline data and the integrated CAD material object model; 3) building the remanufacturing model based on the CAD material object model and projecting the remanufacturing process; and 4) accomplishing the remanufacture of the machining part by the technology of MIG surfacing.