The invention relates to a method for preparing 6- gingerol and 8- gingerol with fresh ginger. It is characterized in that it compries following steps: cutting fresh ginger into sheets, drying at lowtemperature, disintegrating, sifting with screen of 100 order, heating and refluxing and extracting with acetic ester or acetone, or extracting through immersion, extracting for three times, combiningextract liquid, decompressing and recovering solvent, getting extract concretem dissloving it with acetic ester, treating it with chromatographic silica gel and washing it with benzinum purificatum acetic ester with gradient solvent, checking washing process by using TLC, decompressing to recover solvent and getting coarse 6- gingerol and 8- gingerol; washing coarse product with chloroform- carbinol solvent in Sephadex LH20 gel column, checking washing process with TLC, and getting washung liquid containing 6- gingerol and 8- gingerol with higher purity, decompressing to recover solvent and getting pure 6- gingerol and 8- gingerol, checking content with HPLC. The invention is characterized by simple operation, high productivity and production of two kinds of product at the same time.