Abstract: The bow and arrow is not only a crucial long-range weapon in ancient times, but also modern competitive sports of precision and elegance. From primitive single-material hunting bows to composite-material bows dominating pre-gunpowder battlefields, and then to today’s compound bows with exquisite design and excellent performance, the application of mechanical principles plays a key role throughout the bow’s evolution. Inspired by Su Shi's famous poem “drawing the carved bow arching as the full moon”, this paper traces the structural evolution of bows, and analyzes the mechanics of key components of modern compound bows, such as composite-material limbs and eccentric cams. Then it discusses the promoting role of mechanical innovations in achieving lightweight, highly efficient, and stable of bows.