This protocol describes a prospective, multicenter, randomized controlled trial of 600 patients with great saphenous vein insufficiency (C2–C6) treated with endovenous radiofrequency or laser ablation at 7 centers. Patients will be randomly divided into three groups (1:1:1): group for 1 month (OM), 3 months (TM) and 6 months (SM) wearing class II compression stockings (23–32 mmHg). The primary objective is to assess the recurrence of varicose veins at 12 months after the procedure. Secondary outcomes include occlusion rate of the great saphenous vein, quality of life (AVVQ and CIVIQ questionnaires), VCSS score, and postoperative complications such as pain, ecchymosis, or deep thrombosis. Follow-up will take place after 1, 3, 6 and 12 months. The study responds to the lack of evidence on the optimal duration of compression therapy after thermal ablation, where current practice depends on the clinician's clinical judgment. Registration: ChiCTR2100049550.