The invention discloses a method for extracting antipyretic and antitoxic oral solution by using cellulase which aims at providing a method for extracting oral solution with simple operating technology, safety and energy saving. The method of the invention includes the following steps that materials required to prepare 100L antipyretic and antitoxic oral solution are added into 200 to 700L purified water to be then evenly blended; 0.2 to 5kg cellulase is then added into the purified water and evenly mixed, and the obtained mixture then stands still under the room temperature for 15 to 72 hours to realize the full reaction; the mixture after the full reaction is then filtered to collect the filtrate which is condensed to 100L and the pH value of which is adjusted to be 4.3 to 6.0 so as to obtain the antipyretic and antitoxic oral solution. By utilizing the unique activity, the mechanism of functioning under the room temperature and the function of exclusively decomposing plant cellulose of the cellulase and determining the dosage of the cellulase and the technology conditions under the room temperature, the production method of the invention prepares the antipyretic and antitoxic oral solution through a certain period of treatment, filtration and condensation and has the advantages of simple operation, safety, energy saving, less environmental pollution and reduction of the production cost.