Trepanning optics is used for laser drilling process. It enables more precise drilling with fewer heat affected zone. To actually use the trepanning optical module for the laser drilling manufacturing system, it must first be small and light. This paper proposes trepanning optical system using tilting focus lens to ensure the small and light form factor of the trepanning optical system. The size of trepanning could be significantly reduced by removing two wedges from the conventional wedge system. Optical design was completed using optical laser tracing, and the trepanning optical system which was based on the optical design was produced. Drilling processing of 400um thickness steel was performed using the trepanning optics system.