Abstract: The present disclosure belongs to the technical field of tools for bridge reinforcement, and particularly relates to a precisely-positioned drilling apparatus for steel tubular joints. According to the present disclosure, a lifting frame unit, an electric drill, a lever unit, a positioning tube unit, and a diagonal tensioning member unit are arranged on a base unit such that 1. during drilling, a drill rod is not prone to deviation, and a drilling action is relatively precise, resulting in an approximately circular shape of a final drilled hole; and 2. the above lever unit is essentially a labor-saving lever that ensures relatively easy and convenient drilling operations. Additionally, the present disclosure further discloses an application method of the apparatus, which ensures that the apparatus may stably fit with and be safely available for electric drills with various sizes and specifications.