Abstract： Objective： To observe the clinical efficacy of modified Buyang Huanwu Decoction combined with Flunarizine Hydrochloride in the treatment of patent foramen ovale （PFO） -related migraine. Methods：A total of 70 patients with PFO-related migraine diagnosed and treated in the Department of Encephalopathy，the Seventh School of Clinical Medicine，Guangzhou University of Chinese Medicine from December 2023 to March 2025 were selected and divided into the observation group and the control group using the random number table method，with 35 cases in each group. During the study， one case in the observation group and four cases in the control group dropped out. Finally， 65 patients completed the trial，including 34 in the observation group and 31 in the control group. The control group was treated with Flunarizine Hydrochloride Capsules， while the observation group was treated with modified Buyang Huanwu Decoction combined with Flunarizine Hydrochloride Capsules. After one month of continuous treatment， the clinical efficacy and safety were compared， and the changes in migraine attack frequency， Visual Analogue Scale（ VAS） scores of pain，traditional Chinese medicine syndrome scores，Headache Impact Test-6（ HIT-6） scores， hemorheological indicators were respectively compared between the two groups before and after treatment. Results： After treatment，the total effective rate was 91.18%（ 31/34） in the observation group and 58.06%（ 18/31） in the control group， with significant difference between the two groups （P＜0.05）. After treatment， the migraine attack frequency decreased in both groups compared to before treatment （P＜0.05）； the observation group showed a lower attack frequency and a greater reduction than the control group （P＜0.05）. After treatment，the VAS scores decreased in both groups compared to before treatment（ P＜0.05）；the observation group showed lower VAS scores and a greater reduction than the control group （P＜0.05）. After treatment，the traditional Chinese medicine syndrome scores decreased in both groups compared to before treatment （P＜0.05）； the observation group showed lower scores and a greater reduction than the control group （P＜0.05）. After treatment， the HIT-6 scores decreased in both groups compared to before treatment （P＜0.05）； the observation group showed lower HIT-6 scores and a greater reduction than the control group（ P＜0.05）. After treatment，the whole blood viscosity（ at high-shear rate and low-shear rate），plasma viscosity， and fibrinogen concentration decreased in the observation group compared to before treatment （P＜0.05）； and the observation group had lower levels of these four indicators and a greater reduction in each indicator than the control group （P＜0.05）. No serious adverse reactions occurred in either group during the treatment. Conclusion： Modified Buyang Huanwu Decoction combined with Flunarizine Hydrochloride is effective in the treatment of PFO-related migraine. It can reduce the frequency and intensity of migraine attacks， improve the quality of life， alleviate the traditional Chinese medicine syndromes of qi deficiency and blood stasis，and improve the hemorheological status.