The invention relates to a supercritical extract, specifically to a supercritical extract of fresh Cordyceps sinensis and a preparation method thereof, and application of the supercritical extract topreparation of drugs for treating lung cancer. The preparation method for the supercritical extract comprises the following steps: subjecting fresh Cordyceps sinensis to freeze drying, then carrying out crushing and carrying out sieving with a 40-mesh sieve; filling an extraction kettle with the obtained fine powder of Cordyceps sinensis, introducing a supercritical CO2 fluid, setting extraction parameters and carrying out extraction for 1 to 2 h; and collecting an extraction product so as to obtain the supercritical extract of fresh Cordyceps sinensis. The extract provided by the invention isprepared from fresh Cordyceps sinensis through supercritical CO2 fluid extraction, and the obtained extract contains nucleosides, aliphatic acids and sterols and has obvious inhibitory effect on thehuman non-small cell lung cancer A549; the extract is clear in active ingredients and has good application prospects; and the preparation method is free of toxicity and residues during preparation, high in security, simple to operate, high in extraction yield and easy to realize large-scale production.