The clinical pathogenesis of leg weakness is complex. If the symptoms of leg weakness are caused by spleen qi deficiency or qi deficiency, astragalus can be used for treatment as prescribed by the doctor. Astragalus is one of the qi replenishing drugs, which has the effects of replenishing qi and strengthening the spleen, inducing diuresis and eliminating edema, benefiting the guards and consolidating the epidermis, and supporting the toxin to generate muscles (discharging the toxin to promote muscle growth and wound healing), etc. It can be used clinically for treating the evidence of deficiency of the spleen and qi, the evidence of lung qi, the evidence of self-sweating of qi deficiency (involuntary daytime sweating that is aggravated with the slightest movement), as well as the evidence of qi and blood deficiencies. When leg weakness is characterized by spleen qi deficiency or qi deficiency, and there is weakness of the lower limbs, shortness of breath, loss of appetite, and aggravation of symptoms after exertion, astragalus can be used for treatment, and common clinical prescriptions include Astragalus Soup, tonifying the middle and benefiting the qi, and Gui Spleen Soup, etc. The adverse effects of the above prescriptions are not known. The adverse effects of the above prescriptions are not clear. However, it should be noted that not all cases of leg weakness can be treated with Astragalus, and it is necessary to correctly identify the evidence and select the prescription to use the drug, not abuse the drug treatment, and the specific use of the drug need to consult a professional physician’s advice.