The invention discloses a damper with a metal housing. The damper includes a damper outer tube of a damper piston, the damper outer tube being arranged inside the damper with the metal housing, the damper piston dividing a damper internal space filled with fluid into two chambers, the damper piston having a hole and/or a passage gap defined together with an inner wall of the damper outer tube; a damper top end cover and a damper tube bottom end cover respectively arranged at both ends of the damper outer tube; a damper support which is arranged in the damper outer tube and guides a damper pull rod; a damper pull rod connected to the damper piston, the damper pull rod passing through the damper support and extending out from the damper top end cover. The damper tube bottom end cover of the damper with the metal housing in the invention is provided with radial ribs and outer radial grooves which are used for arranging a seal ring and applying extrusion process to the damper outer tube, which solves the problem of proneness to cylinder explosion due to a larger impact force born by the damper. In addition, a slow-speed piston slide cavity and a rapid-speed piston slide cavity of the damper outer tube are connected to form a ladder shape, realizing both fast and slow cushioning strokes.