Steel plate welding machine

The utility model provides a steel plate welding machine, and relates to the technical field of welding machines. The hollow column is fixedly mounted in the center, close to the outer surface of the top, of the vehicle body, and a plurality of sliding grooves are formed in an inner cavity of the hollow column; the through groove is formed in the outer surface, close to the upper end, of the hollow column. A first servo motor is started to rotate forwards, a first gear arranged on the outer surface of a circular shaft in a sleeving mode is driven to rotate, the first gear rotates and drives a supporting column connected with the first gear in a meshed mode through teeth to move upwards in an inner cavity of a hollow column at the same time, and a plurality of sliding grooves are formed in the inner cavity of the hollow column; a plurality of limiters installed at the bottom of a supporting column are movably embedded in an inner cavity of a sliding groove, so that it can be better guaranteed that the supporti