The invention discloses a process for preparing 
heparin sodium through membrane separation. The process comprises the steps: 
intestinal mucosa enzymolysis, 
ceramic membrane 
filtration, 
ion exchange 
column chromatography, nanofiltraiton membrane concentration, 
alcohol precipitation and 
drying, wherein the optimal condition for the 
intestinal mucosa enzymolysis is formed by the proper proportion of 
intestinal mucosa to water, enzymolysis temperature and pH value of a 
system. A 
protease can take the optimal enzymolysis effect, the structure and activity of 
heparin are not damaged when the glucosidic bond linked between 
protein and the 
heparin is hydrolyzed, meanwhile, fewer low-molecular heparins are generated, the activity of the heparin can be improved by 20%, and the generated low-molecular heparins can be reduced by 10%. Due to the adoption of the 
ceramic membrane 
filtration, 
protein impurities and the heparin in an enzymatic 
hydrolysate can be effectively separated, so that the heparin loss is greatly reduced and can be reduced by 5-8% as comparison with that of the traditional process, the production cost is reduced, the discharged 
wastewater can be reduced by 50-60%, the resin utilization ratio can be increased by 40-50%, the consumption of auxiliary materials is low, the quality of the 
heparin sodium is stable, the process is convenient to operate, and the defects such as high 
impurity content in the enzymatic 
hydrolysate, serious waste liquid 
discharge pollution, high personnel 
utilization rate and the like are overcome.