The invention discloses a movable cradle for building bridge guardrail construction. The movable cradle comprises a base, a plurality of travelling mechanisms are arranged on the lower side of the base in a surrounding mode, bottom counterweight blocks fixed to the base are arranged between the multiple travelling mechanisms, a fixing plate is arranged on one side of the base, a vertical rod is vertically arranged on the fixing plate in an inserted mode, and the vertical rod is rotatably connected with the fixing plate; the lower end of the vertical rod is fixedly connected with a steering mechanism, and a controlling handle is fixedly connected to the end, away from the steering mechanism, of the vertical rod; an extension plate is arranged on the side, away from the fixing plate, of thebase; a plurality of first sliding blocks are arranged on the side, close to the base, of the extension plate; and the base is provided with first sliding grooves corresponding to the first sliding blocks. According to the movable cradle for building bridge guardrail construction, the structure is simple, using is convenient, safety of high-altitude construction is high, a large number of scaffoldsupporting systems is saved, a lot of funds is saved, and the movable cradle has the characteristics that construction is safe, moving is convenient and flexible, the floor space during constructionis small, the construction efficiency is high, and benefits are obvious.