1.Laser treatment: there are many kinds of lasers, clinically commonly used Nd:YAG laser, C02 laser two. 1.1 ND:YAG laser The 1064 n m infrared light of ND:YAG laser can be highly selectively absorbed by a large amount of reduced hemoglobin in the vascular malformation tissue, while other tissues absorb very little, so the laser energy is mainly distributed inside the lesion. The light energy acts thermally on the endothelial layer of the blood vessels, producing a selective coagulation and destruction effect. Based on this feature, when the laser is applied to the lesion area, the tumor appears gray or black and shrinks significantly. Other tissues such as muscles, glands, bones, blood vessels and nerves do not show similar changes. Experimental studies have also confirmed that there is a quantitative-effect relationship between ND:YAG laser irradiation and nerve damage, i.e., within the energy density range of ND:YAG laser irradiation for the treatment of vascular malformations, the effect on nerve tissue is less and does not cause nerve dysfunction. Therefore, the ND:YAG laser irradiation method is more suitable for the treatment of diffuse cavernous hemangioma, which has the advantages of less trauma, less bleeding, precise efficacy, and basically no functional disorder after surgery, and has good application prospects. Moreover, surgery combined with ND:YAG laser therapy is suitable for cavernous hemangioma, as long as the hemangioma body can be revealed through surgical flap, and when lesions such as congenital arteriovenous malformation or trabecular hemangioma are excluded, this method can be used for treatment. For diffuse cavernous hemangioma with extensive involvement, especially when the lesion involves the whole limb, staged treatment can be used to avoid drastic one-time tissue damage. 1.2 C02 laser The C02 laser is invisible light with a wavelength of 10.06 u m. It is not very convenient for clinical operation because it is guided by an articulated arm. although the penetrating ability of the C02 laser is not as good as that of the Na: YAG laser, the use of a larger beam of light to irradiate the blood vessels causes them to gradually shrink and become smaller until they are closed, achieving the purpose of cure. The advantages of C02 laser are: (1) C02 laser energy coagulates blood vessels through heat conduction, and has good hemostatic effect. Since the laser energy closes the blood vessels, the recurrence rate is small. (2) C02 laser has a short treatment time for hemangioma, and the patient suffers little pain and does not need special care after treatment. (3) The C02 laser has high energy and high temperature, so the heat treatment of the lesion is free of infection and there is little chance of scarring. (4) C02 laser treatment is simple and suitable for superficial hemangiomas such as capillary dilated granuloma, some herbaceous hemangiomas and spider nevi, and hemangiomas in the oral cavity. 1.3 Laser photodynamic therapy The principle of photodynamic therapy (PDT) is to use photosensitizing agents to produce photochemical reactions after being stimulated by laser or other light sources, and the reaction products such as monomorphic oxygen and free radicals have cell-killing effects, resulting in damage to vascular endothelial cells. The endothelial cells are damaged and the capillaries are occluded after the vessel wall is destroyed and mechanized. Both hydrogen laser photodynamic and hydrogen laser photodynamic are clinically reported to be effective for pemphigoid nevus (PWS) pemphigoid nevus. The main disadvantages of laser photocoagulation are shallow penetration depth into the tissue, non-selective surface skin thermal injury, and scar formation after tissue healing.