Metal guardrail convenient to mount and dismount

The utility model discloses a metal guardrail convenient to mount and dismount, and relates to the technical field of guardrails. The guardrail comprises a vertical rod assembly and a handrail assembly, wherein the handrail assembly is in sliding fit with the vertical rod assembly; the vertical rod assembly comprises a connecting vertical rod; fixed bottom grooves are formed in the peripheral side surfaces of the connecting vertical rods; a threaded rod is rotationally matched with the center of the bottom in the fixed bottom groove. Two symmetrical guide rods are fixed at the bottom in the fixed bottom groove; and two symmetrical limiting rods are fixed at the bottom in the fixed bottom groove. By rotating the threaded rod, the movable plate drives the two connecting insertion rods fixed to the inner wall of the arc-shaped arm to move downwards together while slowly moving downwards on the circumferential side faces of the guide rod and the limiting rod, and the two connecting insertion rods are sequentially