The invention discloses a method for preparing 
enoxaparin sodium, comprising the steps of salinizing, 
drying, esterfying, 
alcohol precipitating, oxidizing, 
alcohol precipitating, fine filtering and 
freeze drying. In the method provided by the invention, a hydrophilic 
liquid phase reaction, a hydrophobic 
liquid phase reaction and a 
solid phase reaction are adopted, so that 
macromolecule sodium heparin is degraded into micromolecule 
sodium heparin with a specific structure, and the molecular weights of products and molecular 
weight distribution ranges are controlled, thus anti-FIIa activity resulting in bleeding risk is greatly reduced, the anti-FXa activity is relatively improved, and the product effectiveness and safety advantages are obvious. The 
enoxaparin sodium can be used for effectively preventing venous thromboembolism and 
pulmonary embolism, can be used for 
thrombosis before and after operations of 
orthopedic surgery and 
neurosurgery, and can be used for greatly reducing apoplexy risk, more effectively reducing death, cardiac failure and recurrent 
angina of patients suffering from unstable coronary 
artery syndromes, reducing 
hypertriglyceridemia and effectively eliminating the side effects of haemorrhage, 
osteoporosis and induced thrombocytopenia after long-term use of common unfractionated 
heparin sodium and derivates of common unfractionated 
heparin sodium.