OBJECTIVE： To observe the efficacy and safety of aspirin combined with Dieda huayu powder in the prevention of deep vain thrombus （DVT） after great saphenous varicose vein surgery. METHODS： 280 patients with great saphenous vein surgery were randomlt divided into control group and observation group. control group was given Aspirin enteric-coated tablet 100 mg breakfast in the next day of surgery， once a day； observation group was additionally given Diedahuayu powder 2 g to fumigate feet and non-operation place on ill leg in the next day of surgery. 7 d was a treatment course. The incidence of prothrombin time （PT）， activated partial thromboplastin time （APTT）， fibrinogen （Fg）， platelet count and the incidence of DVT and adverse reactions after surgery before and after surgery in 2 groups were observed. RESULTS： The incidence of DVT in observation group was significantly lower than control group， the difference was statistically significant（P＜0.05）. After surgery， the PT， APTT and Fg in 2 groups were significantly higher than before， and observation group was higher than control group， platelet count was significantly lower than before， and observation group was lower than control group， the differences were statistically significant（P＜0.05）； there was no significant difference in the incidence of adverse reactions between 2 groups（P＞0.05）. CONCLUSIONS： Aspirin combined with Dieda huayu powder can more effectively prevent the DVT after great saphenous varicose vein surgery than only aspirin， inhibit coagulation， with similar safety.