The incidence of varicose veins in the lower extremities in China is about 10%-30%, which is a common disease and multi-morbidity. Clinical manifestations: superficial venous tortuous dilatation, limb edema, swelling and pain, skin pigmentation, eczema, liposclerosis and even ulcers, commonly known as old rotten feet, reduce the quality of life of patients. The traditional surgical method is high saphenous vein ligation with varicose vein stripping. The surgery is more invasive, with more incisions, scarring and longer recovery time. Minimally invasive endovenous laser treatment of varicose veins in the lower extremities has less damage, fewer complications, faster recovery, no scars, and some patients can achieve cosmetic results. The procedure uses the thermal energy of the laser and the laser effect of special tissues to induce thrombosis throughout the veins and eventually contract and close them, thus achieving the treatment of varicose veins. The procedure is performed by puncturing the saphenous vein with an 18G trocar needle in front of the medial ankle, removing the needle core, feeding a 0.035 ultra-smooth, ultra-long guidewire from the trocar to the junction of the saphenous vein and the femoral vein, withdrawing the trocar, feeding a catheter sheath along the guidewire, and advancing the 4F catheter through the sheath to 1 cm below the junction of the saphenofemoral vein. -After 5 cm, the saphenous vein was double ligated 1 cm below the junction of the saphenofemoral vein, and the guidewire was withdrawn and fed into the optical fiber through the catheter, with the head end of the optical fiber located 1 cm below the ligature of the saphenous vein, and the head of the optical fiber breaking 5 cm beyond the head end of the catheter. According to the location of the red indicator at the head end, stimulate photocoagulation to retreat the catheter and fiber simultaneously, the fiber travels at a speed of 3mm/s during photocoagulation, while wet gauze compresses the skin of the photocoagulation site to make the local varicose vein empty, to the ankle incision to draw out the cannula and fiber in turn and stop photocoagulation. For patients with severe twisted saphenous vein in the calf or knee area, combined with saphenous vein thrombosis and local sclerotherapy injection, laser closure can be performed along the saphenous vein in sections.