The invention discloses a method for extracting general flavone from sorrel shell waste residues through microwave refluxing. The method comprises the following specific steps of: 1, removing impurities from naturally-dried sorrel shells, smashing, sieving with a sieve of 40-60 meshes, and putting into a constant-temperature drying oven for drying sorrel shell powder for later use; and 2, uniformly fixing the powder treated in the step 1 with 30-60 percent of ethanol in the weight volume ratio of 1:25-1:50, performing reflux leaching at microwave power for 10-25 minutes, performing suction filtration to obtain a general flavone extracting solution, removing ethanol by rotationally evaporating, and performing vacuum drying to obtain a general flavone solid. The content of general flavone in a concentrated solution is measured with an aluminum chloride colorimetric method. According to measurement, the extraction ratio of general flavone is 95 percent, and the yield is 0.20 percent. The method has the advantages of quickness, high extraction ratio, environmental friendliness and nontoxicity by taking ethanol water as a solvent, simple equipment operation, small solvent using amount, easiness for recovering and suitability for expanded production in plants. The method has wide application prospects in medicines and foods.