MicrOwave and laSer ablaTion Study (MOST Study)

Inclusion Criteria: 1. Age 18 years or older, not older than 80 years, male or female 2. Patients clinically diagnosed as primary great saphenous vein insufficiency with reflux lasting \> 0.5 seconds on duplex ultrasound 3. Patients with CEAP grade C2-C6 4. Patients who voluntarily participate in this trial, understand all the risks and benefits described in the informed consent document, and sign the written informed consent form Exclusion Criteria: 1. Patients with diameter of target lesion vein \< 2 mm or \> 15 mm 2. Patients with previous surgical treatment on the target lesion or patients with acute thrombosis 3. Patients with deep vein thrombosis and superficial vein thrombosis 4. Patients with acute systemic infectious diseases 5. Patients with severe liver and kidney dysfunction (ALT \> 3 times the upper limit of normal value; creatinine \> 225 umol /L) 6. Patients with known uncorrectable bleeding or severe coagulopathy 7. Patients with anesthesia contraindications 8. Patients with poorly controlled hypertension (systolic blood pressure ≥ 160 mmHg and/or diastolic blood pressure ≥ 100 mmHg) and diabetes mellitus (fasting glucose ≥ 10.0 mmol / L) 9. Patients with non-primary varicose veins caused by post-deep vein thrombosis syndrome, KT syndrome (Klippel-Trenaunay syndrome), arteriovenous fistula, etc. 10. Patients with other diseases that may cause difficulty in conducting the trial or evaluation, such as mental illness, AIDS, malignant tumors, liver disease, cardiac insufficiency, etc. or patients whose life expectancy is less than 1 year 11. Pregnant, lactating women, or those planning on becoming pregnant during the trial 12. Patients who have participated in clinical trials of other drugs or medical devices in the past 3 months 13. Patients considered unsuitable for inclusion by investigators for other reasons