Abstract： Objective： To observe the clinical efficacy of Maitongning Decoction as adjuvant therapy to endovenous microwave ablation （EMWA） in treating great saphenous vein varicose. Methods：A total of 124 patients with great saphenous vein varicose admitted to the Second People's Hospital of Henan Province from January to October 2023 were enrolled and randomly divided into a control group and an observation group （n = 62 each） by a random number table method. Both groups underwent EMWA；the control group received subcutaneous low-molecular-weight heparin sodium starting on post-operative day 1， while the observation group additionally received oral Maitongning Decoction， both groups were treated for two weeks. Clinical efficacy， incidence and recurrence of lower-limb deepvein thrombosis （DVT），traditional Chinese medicine syndrome scores，Venous Clinical Severity Score（ VCSS） scores， haemodynamics，inflammatory indices [interleukin-2（ IL-2），interleukin-6（ IL-6），interleukin-10（ IL-10）]，and serum levels of serpine1 and Kruppel-like transcription factor 2 （KLF2） were compared. Results：Total effective rate was 98.39% （61/62） in the observation group，which was higher than 87.10% （54/62） in the control group （P＜0.05）. Both groups’ traditional Chinese medicine syndrome scores and VCSS scores went down over time （P＜0.05）. After 7 and 14 days of treatment， traditional Chinese medicine syndrome scores and VCSS scores in the observation group were lower than those in the control group at the same time points （P＜0.05）. Whole-blood low-shear viscosity，highshear viscosity， and plasma viscosity in both groups also went down over time （P＜0.05）； after 7 and 14 days of treatment，whole-blood low-shear viscosity，high-shear viscosity，and plasma viscosity in the observation group were lower than those in the control group at the same time points （P＜0.05）. The levels of IL-2， IL-6， and serpine1 declined，whereas IL-10 and KLF2 levels increased over time （P＜0.05）；after 3，7，and 14 days of treatment，the observation group exhibited lower IL-2，IL-6，and serpine1，as well as higher IL-10 and KLF2 levels than the control group at the same time points（ P＜0.05）. The recurrence rate was 0（ 0/59） in the observation group versus 5.66%（ 3/53） in the control group，with no significance in the difference（ P＞0.05）. Post-operative DVT incidence was 1.67%（ 1/60） in the observation group，lower than that of 16.39%（ 10/61） in the control group（ P＜0.05）. Conclusion：Maitongning Decoction combined with EMWA can effectively improve clinical outcomes of great saphenous vein varicose. It can reduce mild inflammation responses， improve haemodynamics， adjust the expression of serum KLF2 and serpine1 levels，and lower the risk of DVT after surgery.