The utility model discloses a weld assembled ladder, including the ladder protect head, crossbeam, attend the group, fixed plate, free bearing board, articulated slab, packing ring, backup pad, lying, long crossbeam and shrouding, the top of going up the group is equipped with the ladder and protects the head, two it links to each other through the crossbeam to go up the group, on help the lower part to be equipped with two the fixed plate, the bottom of going up the group is equipped with the free bearing board, the bottom of free bearing board is equipped with the articulated slab, go up in the group the articulated slab with set up articulated slab at the lying top and pass through the bolt and link to each other, be equipped with the packing ring between two articulated slabs, two the lying links to each other through long crossbeam, the lying is lieing in be equipped with the shrouding on the body of rod at long crossbeam both ends. The utility model discloses, pass through welding technique to and the close cooperation of each part, make this ladder working property stable, the phenomenon can not appear rocking, simultaneously, this physique simple structure, reasonable in design.