The utility model discloses a pipe fitting side piercing press, moreover, the steam generator is simple in structure, it includes the bearing to provide the clamp force through punching press mechanism, bearing upper portion is opened flutedly, be equipped with the locating plate that is used for the pipe fitting location in the recess, be equipped with the drift that can vertically move in the pros of locating plate, the drift upper end is fixed on the pressed sheet, upper portion at the locating plate is equipped with elastic pressure plate, the last face of locating plate is opened there is round arc positioning groove, elastic pressure plate's lower face is opened has convex indent, indent and constant head tank form the location portion of pipe fitting relatively, the lower part of pressed sheet is fixed with the backing plate, the backing plate is the elastic pressure plate that compresses tightly in vogue under the drift, and last the opening of elastic pressure plate has the via hole that supplies the drift to pass through.