Welding smoke and arc are extremely occupational hazards to the operators. A mobile welding protective device is designed for scattered welding operation. In order to protect operators from welding arc injury and collect welding smoke, a novel welding covering is designed for use of purification device. On the other hand, owing to the large amount of welding smoke, the ordinary filtering material is not suitable for welding smoke purification; the metal-cotton is utilized to pre-filter the welding smoke. In the end, the protective device against welding arc and smoke is designed and tested. The device is effective for mobile welding operation.