Abstract: The welding technology of prefabricated parts with suspension characteristics was studied by combining the augmented material manufacturing with arc welding robot technology. Firstly, the algorithm of prefabricated parts forming dimension prediction is optimized to realize the prediction of forming height and width. Aiming at the phenomenon of downward flow of suspended weld, the influence of inclination angle of welding torch on weld formation was studied, the optimum inclination angle range of welding torch was determined, and the forming method was validated by design and experiment. The forming quality of suspended weld surface is effectively improved. Based on this, an algorithm for predicting inclination angle of welding torch was proposed to realize the prediction of inclination angle of welding torch in suspended weld process. Finally, welding prefabricated parts with suspension characteristics verifies the accuracy of prediction algorithm and forming method. The test results showed that the surface forming quality of prefabricated parts is good and the forming size error is less than 1 mm.