Abstract： Objective： To observe the clinical efficacy of Shengxian Decoction combined with Ganglioside in treating cerebral watershed infarction （CWI） and its effects on cerebral blood flow perfusion， blood viscosity， and neurological function in patients. Methods： A total of 108 patients with CWI treated at Ninghai County Hospital of Traditional Chinese Medicine from March 2020 to January 2022 were selected as research subjects and divided into a control group and an observation group，with 54 cases in each group，using a random number table method. The control group received Ganglioside treatment， while the observation group received Shengxian Decoction combined with Ganglioside on the basis of the control group. Both groups were treated continuously for 14 days. Traditional Chinese medicine syndrome scores，National Institutes of Health Stroke Scale （NIHSS） scores，cerebral blood flow perfusion indicators [cerebral blood volume （CBV），cerebral blood flow （CBF），and mean transit time （MTT）]，blood viscosity indicators [platelet aggregation rate， plasma viscosity， whole blood viscosity at low shear （NBL）， and whole blood viscosity at high shear （NBH）]，neurological function indicators [ubiquitin carboxyl-terminal hydrolase-1（ UCH-L1）， glial fibrillary acidic protein （GFAP），and neuron-specific enolase （NSE）]，and inflammatory factors [tumor necrosis factor-α （TNF-α），matrix metalloproteinase-9 （MMP-9），and interleukin-6 （IL-6）] levels were compared between the two groups before and after treatment， and the clinical efficacy of the two groups was assessed. Results： After treatment，the cured and markedly improved rate in the observation group was 96.30%（ 52/54），higher than that in the control group at 90.74%（ 49/54）（ P＜0.05）. After treatment，CBV and CBF were increased in both groups（ P＜0.05）， with the observation group achieving higher levels than the control group （P＜0.05）. After treatment， traditional Chinese medicine syndrome scores， MTT， platelet aggregation rate， plasma viscosity， NBL， NBH， UCH-L1， GFAP，NSE，TNF-α，MMP-9，and IL-6 were all decreased in both groups （P＜0.05），with the observation group achieving lower levels than the control group （P＜0.05）. Conclusion：Shengxian Decoction combined with Ganglioside has a good therapeutic effect on CWI， effectively improving cerebral blood flow perfusion， reducing blood viscosity， alleviating neurological dysfunction，and reducing inflammatory responses.