The invention discloses unibract fritillary bulb lung-heat-clearing syrup, and belongs to the field of pharmacy. The unibract fritillary bulb lung-heat-clearing syrup is prepared by performing ultra-critical CO2 extraction on the following raw materials in parts by weight at three stages: 200-300 parts of loquat leaf, 40-60 parts of bitter almond kernel, 3-8 parts of unibract fritillary bulb, 30-80 parts of dwarf lilyturf root, 30-80 parts of rehmannia, 30-80 parts of liquoric root, 20-40 parts of platycodon root, 10-25 parts of peppermint, 100-200 parts of sugar cane and 400-600 parts of isomalto-oligosaccharide, wherein process parameters of each stage are that: at the first stage, the pressure is 50-60 MPa, the temperature is 25-35 DEG C, and the extraction time is 30-60 minutes; at the second stage, the pressure is 30-40 MPa, the temperature is 40-55 DEG C, and the extraction time is 20-40 minutes; at the third stage, the pressure is 15-20 MPa, the temperature is 60-80 DEG C, and the extraction time is 5-10 minutes.