Born in the United States in the 1960s, the laser is a new artificial light source with high energy, high intensity and high directionality. The human eye is particularly well suited for laser treatment. The purpose of laser treatment in diabetic retinopathy is to close the neovascularization of the retina, which is prone to hemorrhage, and to destroy the substances in the fundus that stimulate neovascularization, so that the production of neovascularization is reduced, and also to degenerate the neovascularization that has been produced. This allows the relatively hypoxic retinal tissues to be reduced in oxygen consumption due to the destruction of the retina by the laser, and the remaining retinal tissues to be relieved of hypoxia and no longer produce neovascularization. This effect can never be replaced by medications as most patients’ eyes remain in a stable state with no further progression of lesions after treatment. Laser treatment can be performed on an outpatient basis, is simple, convenient and reliable, but is generally performed in sessions (usually 4), each 1-2 weeks apart, in order to reduce the reaction to laser treatment. Laser treatment also has its shortcomings. The laser treatment site is strictly defined, the orthoptic papilla (i.e. the nerve concentration in the eye to the back of the eye) and the most sensitive macula and its surrounding area are the forbidden area of the laser, outside the forbidden area can be photocoagulated, photocoagulation not only destroys the lesion area, but also destroys part of the normal area, the result is to damage part of the useful vision, or to reduce the scope of seeing, but can achieve long-term preservation of the most useful central The result is that some of the useful visual acuity is damaged, or the range of vision is reduced, but the most useful central vision can be preserved for a long time, that is, “sacrificing the carriage and horse to protect the general”.