NOVELTY - A curcumin is extracted from rhizoma curcumae longae by cleaning and drying rhizoma curcumae longae, crushing into 20-40 meshes rhizome curcumae longae powder, mixing powder with extraction solvent, refluxing and extracting for 1-3 times, combining extract liquids, filtering and separating to remove material dregs, decompressing and concentrating filtrate at below 70 degrees C, adding water, decompressing and concentrating until there is no extraction solvent, and separating out extraction solvent to obtain concentrated liquid.    USE - Method for the extraction of curcumin from rhizoma curcumae longae (claimed).    ADVANTAGE - The method has short process for separating and purifying heavy metal and no risk of secondary pollution caused by additional absorbent or absorption medium. The heavy residue in the product can be purified to lead content of less than 1 ppm, cadmium content of less than 1 ppm, mercury content of less than 0.1 ppm and arsenic content of less than 0.1 pm.    DETAILED DESCRIPTION - Extraction of curcumin from rhizoma curcumae longae comprises cleaning and drying rhizoma curcumae longae, crushing into 20-40 meshes rhizome curcumae longae powder, mixing rhizoma curcumae longae powder with extraction solvent at kg/L ratio of 1:6-8; stirring, refluxing and extracting for 1-3 times, combining the extract liquids, filtering and separating to remove material dregs, decompressing and concentrating the filtrate at below 70 degrees C, pumping vacuum to make the pressure at - 0.07-- 0.095 MPa in decompressing and concentrating process, adding water, decompressing and concentrating until there is no extraction solvent, and separating out extraction solvent and obtaining concentrated liquid, where extraction solvent is methanol aqueous solution having 80-85 vol.% concentration, ethanol aqueous solution having 75-80 vol.% concentration or acetone aqueous solution having 65-70 vol.% concentration; and#separating to remove heavy metal by cooling the concentrated liquid to room temperature, standing and depositing, separating out upper layer clear liquid, discarding supernatant liquid, adding water having 0.4-0.5 times weight of rhizoma curcumae longae powder into the obtained sediment, heating up to 60-80 degrees C, stirring, cooling to room temperature, standing and depositing, separating and discarding the supernatant clear liquid to obtain the sediment; and#mixing the sediment with a water-containing polar solvent at kg/L ratio of 1:5-10;#heating until fully dissolved, cooling to room temperature, standing, depositing and crystallizing, washing sediment crystal for 1-3 times into a washing solvent to obtain crystal high purity curcumin, where ratio of sediment crystal to washing solvent is 1:3; and water-containing polar solvent is methanol aqueous solution having 40-50 vol.% concentration, ethanol aqueous solution having 70-80 vol.% concentration, acetone aqueous solution having 50-60 vol.% concentration, methanol, ethanol having concentration of greater than or equal to 95% or acetone.