Abstract Welding, as an important process for body-in-white (BIW), it should be taken into consideration in the automobile industry where the spot welding is often used. In order to validate the welding process of the whole welding line, the simulation process for the body side which is an important part of the BIW is discussed in the software Delmia according to the layout in AutoCAD which has been designed before. And then the establishment of model, the welding process and the specific working procedures are considered and discussed in the design stage to guarantee that the simulation process in Delmia can be carried on to validate whether the designed process can meet the working requirements. Additionally, the welding operation by multi-robots in a work station is analysed to verify that the number of robots and their positions are acceptable and they can reach working positions. Finally, the planning of the cycle time is obtained and then we can conclude that the designed welding process is feasible to guide the work in site.