The utility model relates to a welding device for quickly calibrating and fixing sheet metal parts, which belongs to the technical field of sheet metal parts and is characterized by comprising a supporting seat. The mounting blocks are symmetrically mounted at the top of the supporting seat; the arm plate is hinged between the mounting blocks through a rotating rod, and the section of the arm plate is L-shaped; the electrode holder is detachably mounted at one end, far away from the supporting seat, of the arm plate and is used for clamping a welding rod; wherein the driving assembly is installed on the supporting base and used for driving the arm plate to rotate, the supporting base comprises an upper support and a lower support, the outer wall of the lower support is sleeved with a sleeve, the upper support is connected to the inner wall of the sleeve in a sliding mode in the vertical direction, and a lifting assembly used for driving the upper support to ascend and descend is further arranged between the upper support and the lower support. When the welding device is used, the welding device can replace manual work to weld the preset position of the sheet metal part in an all-around mode, the application range can be enlarged, and the influence on surrounding workers in the welding process can be reduced.