The invention provides an automated tool for binding steel bars and an application method thereof. By means of the automated tool for binding the steel bars, the problem that steel bars in the depth of a steel bar cage are difficult to bind is solved, and efficiency of binding steel bar cages is improved. According to the provided automated tool for binding the steel bars, because a connecting rodis movably connected with a main rotary motor and a binding operating head respectively, the length of the connecting rod can be adjusted according to the depth of the position, in a steel bar cage,of a to-be-bound steel bar, the binding operating head is conveniently stretched to the position of the to-be-bound steel bar, and thus the problem that the steel bars in the depth of the steel bar cage are difficult to bind is solved. Besides, because the binding operating head is arranged at the front end of the automated tool for binding the steel bars, the binding wire is delivered directly from the binding operating head, the distance of wire feeding is shortened, and thus the probability of occurrence of breakdown in the wire feeding process is also reduced, and reliability of the equipment is improved.