The invention provides a 
Mactra veneriformis glycosaminoglycan extraction method, which is characterized by comprising the following steps of: weighing the soft part of 
Mactra veneriformis, adding water to prepare into a homogenate with the ratio of water to material being 3:1, adding neutral 
subtilisin and 
trypsin into the homogenate for 
enzymatic hydrolysis while the ratio of 
bacillus subtilis neutral proteinase to 
trypsin is 4:3, the addition of compound 
enzyme is 1% and the 
hydrolysis time is 3-5h, boiling and centrifuging the enzymolysis liquid to obtain a 
clear liquid, adding 
active carbon for decolouring, followed by vacuum 
filtration, filtering with the assistance of diatomite, carrying out 
alcohol precipitation to obtain crude 
glycosaminoglycan with the 
yield rate being more than 1.3%, preparing 3% of a 
sugar solution, centrifuging to remove acidic and neutral proteins, followed by 
dialysis of a supernatant and 
alcohol precipitation, preparing 1% of a 
sugar solution, adding 5% of CTAB, centrifuging, dissolving the precipitate into a KCI solution to obtain a dissociation liquid, carrying out 
alcohol precipitation, followed by 
dialysis and alcohol precipitation to obtain high-purity 
glycosaminoglycan. The method provided by the invention has advantages of mild reaction condition and high 
yield rate and purity. Lots of proteins can be recovered while extracting glycosaminoglycan. The extracted substance has important effects of removing free radial, resisting oxidation and resisting coagulation. The 
yield rate of crude glycosaminoglycan reaches over 1.3% and the purity of glycosaminoglycan reaches more than 95%.