The invention discloses a method for extracting rosavin from Rhodiola rosea. The method includes the following steps that 1) the Rhodiola rosea is used as a raw material, a 60%-70% ethanol solution is used for conducting reflux extraction, after an extracting solution is concentrated, centrifuging is carried out, a liquid supernatant is washed until effluent is clarified through a chromatographic column filled with macroporous resin, elution is carried out first by using a 15%-25% ethanol solution, then elution is carried out again by using a 60%-70% ethanol solution, and after concentration and drying are completed, a crude extract is obtained; 2) subcritical extraction is conducted on the crude extract by using dichloromethane as an extraction agent, the injection rate of the extraction agent is one to two times of the weight of the crude extract, the extraction temperature is 38-42 DEG C, the extraction pressure is 2.3-2.7MPa, the extraction time is 20-40min, and after the self-volatilized dichloromethane is recycled, a finished product can be obtained. The method for extracting the rosavin from the Rhodiola rosea is simple in step, short in used time and few in dosage of reagents, the yield is about 1.5%, the content of the rosavin is about 80%, the yield and the purity are high, and therefore the method is more suitable for industrial production.