The invention discloses an optical system for generating a hollow beam by focusing a Bessel-Shell model light field through axicons.The optical system comprises an optical platform.A laser device is placed on the optical platform.A collimation and beam expanding system, an aperture diaphragm, the first axicon, a first thin lens, rotary ground glass, a second thin lens and the second axicon are sequentially placed along an optical path of the laser device.By means of the technology, the hollow beam of the size increasing along with increase of the distance can be generated, and the hollow beam has a self-reconstruction characteristic.The optical system has the advantages that the optical structure is simple, optical elements are cheap, and the generated hollow beam is high in quality; a powerful means will be provided for people to trap particles of different sizes and numbers on multiple layers.