Abstract：Objective：To observe the clinical effect of acupuncture acupoint selection guided by the theory of yin deficiency in the treatment of lower-limb hemiplegia after stroke and its impact on lower-limb muscle tone. Methods： A total of 96 patients with lower-limb hemiplegia after stroke admitted to Pinghu Traditional Chinese Medicine Hospital from January 2020 to January 2022 were selected and randomly divided into the acupuncture group and the conventional group according to the random number table method， with 48 cases in each group. Based on actively controlling the primary diseases， the conventional group received conventional rehabilitation treatment， and the acupuncture group received acupuncture treatment based on the guidance of acupoint selection by the theory of yin deficiency in addition to the conventional treatment. Both groups were treated continuously for three months. The clinical effects were compared between the two groups；the changes in lower-limb muscle tone，motor function，hemorheological indicators，balance and mobility，and quality of life before and after treatment were compared between the two groups. Results：The total effective rate of treatment in the acupuncture group was 87.50% （42/48）， which was higher than that in the conventional group，70.83% （34/48） （P＜0.05）. After treatment，the whole blood viscosity，plasma viscosity，and hematocrit in both groups were decreased （P＜0.05），and these indicators were lower in the acupuncture group than in the conventional group （P＜0.05）. After treatment，the Modified Ashworth Scale（MAS） scores in the two groups were decreased （P＜0.05），with the acupuncture group showing lower scores than the conventional group （P＜0.05）；the simplified Fugl-Meyer Assessment （FMA） scores in both groups were increased （P＜0.05）， and the scores in the acupuncture group were higher than those in the conventional group （P＜0.05）. After treatment， the Berg Balance Scale（BBS） and the Elderly Mobility Scale（EMS） scores in both groups were increased （P＜0.05），with higher scores in the acupuncture group than in the conventional group （P＜0.05）. After treatment， the Modified Barthel Index Scale （MBI） and Satisfaction with Life Scale （SWLS） scores in both groups were increased （P＜0.05）， and the acupuncture group had higher scores than the conventional group （P＜0.05）. Conclusion： Acupuncture acupoint selection by the theory of yin deficiency in the treatment of lower-limb hemiplegia after stroke have better efficacy，and can improve the hemorheological indicators of patients，enhance their lower-limb muscle tone and motor and balance functions，and improve the quality of life of patients.