Burn scar is an abnormal tissue formed during the self-repair process of skin tissue after burn. Once the scar undergoes excessive hyperplasia, it will not only seriously damage the appearance of patients, but also greatly limit the normal function of the limbs, thus significantly reducing the quality of life of patients. In recent years, with the development of optoelectronic technology, fractional carbon dioxide laser has been widely used in the field of scar treatment. Fractional carbon dioxide laser is a minimally invasive and highly efficient treatment method, and it is also an important treatment method for burn scar. By stimulating the regeneration and repair mechanism of the skin, fractional carbon dioxide laser can accurately remove the diseased tissue, and promote the softening, flattening and functional recovery of the scar. This paper reviews the treatment principle, technical characteristics and clinical application of fractional carbon dioxide laser in the treatment of burn scar, and analyzes the corresponding treatment plans and effects for different scar types, in order to provide theoretical support and practical guidance for relevant clinical scholars.