System for welding vehicle body and using method thereof

The invention discloses a system for welding a vehicle body. The system comprises a vehicle body conveying track 1, a clamp assembly 5 and clamp conveying mechanisms used for conveying the clamp assembly 5. The two sides of the vehicle body conveying track 1 are provided with the clamp conveying mechanisms. Each clamp conveying mechanism comprises clamp storage mechanisms, a Y-direction sliding mechanism 2, an X-direction horizontal movement mechanism 3 and an assembling station 4, wherein the clamp storage mechanisms are arranged on the two sides of the Y-direction sliding mechanism 2 respectively, the Y-direction sliding mechanism 2 is communicated with the X-direction horizontal movement mechanism 3, and the X-direction horizontal movement mechanism 3 is communicated with the assemblingstation 4. The clamp assembly 5 is conveyed to the Y-direction sliding mechanism 2 through the clamp storage mechanisms and then conveyed to the X-direction horizontal movement mechanism 3 and reaches the assembling station