The virtual welding simulation system provides an virtual training environment for welding manipulators. By using the virtual simulation system, the manipulator could simulate the welding process and welding parameter. For such a system, collision detection is the key technology to determine whether the virtual object has been collided in virtual scene. Precise and rapid collision detection algorithms play a vital role on the authenticity and interaction of the virtual reality. In thesis, we deal with the collision detection with the background of virtual welding simulation. To improve the efficiency, the conventional collision detection has been improved in several different aspect.