The invention discloses an ephedra-houttuynia cordata oral liquid and a preparation method thereof. The preparation method comprises the following steps of: weighing ephedra, scutellaria baicalensis, houttuynia cordata, herba andrographitis and isatis root; distilling the ephedra and the houttuynia cordata through steam, and collecting the volatile oil; mixing the residual liquid and residual liquid of the scutellaria baicalensis and the ephedra and houttuynia cordata, decocting the mixture, concentrating the filtrate, precipitating filtrate by alcohol, adding alcohol again after precipitation, filtrating and recycling; and reflux-extracting the herba andrographitis and the isatis root respectively by alcohol, mixing all extracts with the volatile oil, adding water properly, controlling the relative density within 1.02 to 1.15, and sterilizing to obtain the oral liquid. The oral liquid solves the problem of inconvenient quantitative dosing of pulvis; more importantly, in selection of drug components and the method, different medicinal materials are purified by different extracting methods, thus the curative effect of the oral liquid is greatly improved.