The invention belongs to the field of 6-gingerol extraction, and particularly relates to a method for extracting 6-gingerol with the content larger than or equal to 98%. The method for extracting 6-gingerol with the content larger than or equal to 98% comprises the following steps: crushing fresh ginger, adding ethyl alcohol for flash extraction, and separating out a filtrate; concentrating the obtained filtrate, carrying out alumina column chromatography, and collecting an alumina column chromatography eluent; adsorbing the alumina column chromatography eluent through a macroporous resin column, eluting with alkali-containing ethanol, acid-containing ethanol and 50-60 vt% ethanol in sequence, collecting 50-60 vt% ethanol eluent, and concentrating to prepare a concentrated solution with the baume degree of 10-15; mixing the obtained concentrated solution with an organic solvent, adjusting the alcohol concentration to 55-60 vt%, adding activated carbon, and filtering with an organic membrane; and performing gradient elution separation on the obtained filtrate by using macroporous resin through 50-60 vt% ethanol and 65-70 vt% ethanol in sequence, respectively collecting each gradient eluent, concentrating and drying to obtain the required 6-gingerol. The original extraction method is replaced by flash extraction, so that the production efficiency is greatly improved, and various data of series macroporous resin purification are optimized to achieve the maximum efficiency.