Weightlifting is a very healthy exercise. As concerned, an overloaded training or an incorrect technological movements can often easily cause sports injuries. The invention mainly provides a safety structure which is similar to an original weightlifting process. If the barbell falls down unexpectedly, the structure will support the barbell, keeping the lifters from getting injured. For the invention, the safety structure is only assembled of mechanical structure. The product is low cost and is easily to be installed. The lifter can operate conveniently and safely. The invention has already been patented and has won numerous Invention Awards.