Production and purification process of high-purity low-molecular-weight heparin sodium

The invention discloses a production and purification process of high-purity low-molecular-weight heparin sodium, and the proocess comprises the following steps of: S1, weighing 80-120g of crude heparin sodium, performing dissolving with purified water, controlling the temperature of the solution to be below 30DEG C, and conducting stirring for dissolving to prepare a 10%-20% (w/v) crude heparin sodium solution; S2, adding the crude heparin sodium solution in a NaCl solution with a concentration of 2% to prepare a 5%-10% (w/v) crude heparin sodium solution, adding alkaline protease, and carrying out heat preservation enzymolysis at 35-50DEG C for 3-6h to obtain an enzymatic hydrolysate; and S3, carrying out centrifugal separation on the enzymatic hydrolysate obtained in S2 to obtain a supernatant and a precipitate, and discarding insoluble impurities. According to the method, macromolecular substances such as residual protein in the produced low-molecular-weight heparin are interceptedby using an ultrafiltrat