As one of the most common functional disabilities in stroke patients with hemiplegia, poststroke strephenopodia (PSS) seriously affects the life quality of patients, and causes mental and emotional disorders. Some studies have suggested that the traditional Chinese medicine fumigation therapy could be an effective intervention method for patients with PSS. This study aims to investigate the biomechanical effect of the classic prescription peony and licorice decoction (PLD) fumigation treatment for PSS. This study is a multicenter, randomized, placebo-controlled, double blind trial. A total of 190 patients with PSS according to the inclusion criteria will be recruited in 3 centers and randomly distributed to either the intervention group or the control group in a 1:1 ratio. The intervention group will receive PLD fumigation treatment, while the control group will receive placebo fumigation treatment. All patients will receive standardized modern rehabilitation treatment according to the "Chinese Guidelines for Stroke Rehabilitation" (2011 version). The primary outcome measure is medial plantar area (Metatarsal 1+ Metatarsal 2 + Heel Medial) generating from the RSSCAN gait system. The secondary outcome measures contain the scores of clinical scales including Berg Balance Scale, Fugl-Meyer Assessment, Modified Ashworth Scale, Barthel Index, and Stroke-Specific Quality of Life Scale. All assessments will be implemented at baseline, 4 weeks after intervention and at the end of 3 months' follow-up. Intention-to-treat analysis and per-protocol analysis will be applied in this trial. The results of this study are expected to verify the clinical effect of PLD fumigation treatment for strephenopodia after stroke, and to explore the related biomechanical mechanisms by objective evaluation parameter. Chinese Clinical Trial Registry, ChiCTR2000032433. Registered on 28 April 2020. http://www.chictr.org.cn/showprojen.aspx?proj=52644.