Abstract: In order to adopt laser-welding technology in automotive body in white(BIW) welding production line, combining automatic control technology, communication technology with laser-welding technology, an automotive BIM laser welding production line was designed with programmable logic controller and industrial computer as the control core and assisted control core respectively, which could communicate with the fiber laser and the welding robot in real-time. By changing the welding parameters，the laser-welding results of left front door parts of a vehicle were compared with those of spot welding. The results show that: laser welding has several advantages of obviously improved welding speed, flexible control and higher welding strength increased by 70%. This provides a new welding production line technology for the development of miniaturization, lightweight Chinese automobiles with stronger comprehensive mechanical property in their bodies