The invention discloses a multiplication-variable hook device, comprising a hook, a fixed pulley bracket, a movable pullet bracket, a first pulley, a second pulley and a third pulley, wherein the hook is fixed on the movable pullet bracket, the first pulley is fixedly connected with the fixed pulley bracket, the second pulley and the third pulley are symmetrically fixed on the movable pullet bracket, and the second pulley, the first pulley and the third pulley are sequentially wound via a raising line. The hook device overcomes the deficiencies in the prior art, has no need of replacing the hook and putting the raising line through again, and can prominently complete multiplication conversion only by raising the multiplication-variable hook device to a top fixed end and then putting a pinthrough a pin hole of the top fixed end, thus saving a large amount of manpower, materials and time in particular and greatly enhancing efficiency; in addition, due to the installation of an automatic pin-through device and devices fitted therewith, high-altitude operation by workers is totally avoided so as to prevent the occurrence of accidents.