Not knowing about laser technology, laser was first made successfully in 1960. The laser is in the background of theoretical preparation and production practice urgent need arises at the historic moment, it came out, obtained extraordinary rapid development, the development of laser not only makes the ancient optical science and optical technology to obtain a new life, but also leads to the emergence of a whole new industry. Laser cutting machine laser can effectively make people use of unprecedented advanced methods and means, to obtain unprecedented benefits and results, thus promoting the development of productivity. However, like laser laser cutting, laser cutting machine laser welding has been widely used in life and production, and laser crystal, terahertz and other laser knowledge, we have little contact, the author of this paper leads you to understand those we are not familiar with the laser technology. The laser crystal of laser cutting machine can transform the energy provided by the outside world into crystal material with highly parallel and monochromatic laser which is spatially and temporally coherent through optical resonator. It is the working substance of the crystal laser. Laser crystal consists of luminescent center and matrix crystal. The luminescence centers of most laser crystals are composed of activated ions which partially replace cations in matrix crystals to form doped laser crystals. When the activated ions form part of the matrix crystal, they form a self-activated laser crystal. The activated ions used in laser crystal of laser cutting machine are mainly transition metal ions and trivalent rare earth ions. The optical electrons of transition metal ions are 3d electrons in the outer layer, which are easy to be directly affected by the surrounding crystal field in the crystal. Therefore, the spectral characteristics of transition metal ions are very different in crystals with different structure types. The 4F electron of the trivalent rare earth ion is shielded by 5s and 5P outer electrons, so the effect of the crystal field on it is weakened. However, the perturbation of the crystal field makes it possible for the 4F electron transition, which was originally forbidden, to produce narrow band absorption and fluorescence spectrum lines. So the spectra of trivalent rare earth ions in different crystals do not vary as much as transition metal ions.